Joseph Mack

jmack (at) wm7d (dot) net

v2012.01 Jan 2012, released under GPL. Note: Mar 2014 This HOWTO is no longer being maintained.


Install, testing and running of a Linux Virtual Server with 2.2.x, 2.4.x, 2.6.x kernels

search the LVS documentation

Hank Leninger's searchable mailing list archive has moved. It's now at

Table of Contents

1. LVS: Introduction
1.1. Thanks
1.2. About the HOWTO
1.3. Nomenclature/Abbreviations
1.4. Minimal knowledge required
1.5. Free Technical Help
1.6. After you've Got Technical Help
1.7. Paid technical help
1.8. Mailing list: subscribing, unsubscribing, searching
1.9. Mailing list: posting to
1.10. Bug Fixes
1.11. Other load balancing solutions, GPL, opensource and commercial
1.12. Books on LVS
1.13. LVS in the news
1.14. Software/Information/HOWTOs useful/related to LVS
2. LVS: What is an LVS? Can I use an LVS?
2.1. What is a VIP?
2.2. Where do you use an LVS?
2.3. Client/Server relationship is preserved in an LVS
2.4. LVS director is an L4 switch
2.5. LVS forwards packets to realservers
2.6. LVS runs on Linux and FreeBSD directors
2.7. Code for LVS is different for each kernel series
2.8. kernels from 2.4.x series are SMP for kernel code
2.9. OS for realservers
2.10. LVS works on ethernet
2.11. LVS works on IPv6
2.12. LVS is continually being developed
2.13. LVS is 64 bit
2.14. Other documentation
2.15. LVS is not simple to install, get going or keep running
2.16. LVS Control (Failure, Thundering Herd, Sorry Servers)
2.17. clients on realservers
3. LVS: Install, Configure, Setup
3.1. Installing from Source Code
3.2. Ultra Monkey
3.3. Keepalived
3.4. ipvsman(d)
3.5. Alternate hardware: Soekris (and embedded hardware)
3.6. LVS on a CD: Malcolm Turnbull's ISO files
4. LVS: Ipvsadm and Schedulers
4.1. Using ipvsadm
4.2. Memory Requirements
4.3. sysctl documentation
4.4. Compile a version of ipvsadm that matches your ipvs
4.5. put realservers in /etc/hosts
4.6. RR and LC schedulers
4.7. Netmask for VIP
4.8. LBLC, DH schedulers
4.9. LVS with mark tracking: fwmark patches for multiple firewalls/gateways
4.10. SH scheduler
4.11. What is an ActiveConn/InActConn (Active/Inactive) connnection?
4.12. FAQ: ipvsadm shows entries in InActConn, but none in ActiveConn, connection hangs. What's wrong?
4.13. FAQ: initial connection is delayed, but once connected everything is fine. What's wrong?
4.14. unbalanced realservers: does rr and lc weighting equally distribute the load? - clients reusing ports
4.15. Changing weights with ipvsadm
4.16. Setting initial weights
4.17. Dynamically changing realserver weights
4.18. feedbackd
4.19. lvs-kiss
4.20. connection threshold
4.21. Flushing connection table
4.22. Thundering herd problem, Slow start code for realserver(s) coming on line
4.23. Handling kernel version dependant files e.g. and ipvsadm
4.24. Limiting number of clients connecting to LVS
4.25. Who is connecting to my LVS?
4.26. experimental scheduling code
4.27. Ratz's primer on writing your own scheduler
4.28. changing ip_vs behaviour with sysctl flags in /proc
4.29. Counters in ipvsadm
4.30. Exact Counters
4.31. Scheduling TCP/UDP/SCTP/TCP splicing/
4.32. patch: machine readable error codes from ipvsadm
4.33. patch: stateless ipsvadm - add/edit patch
4.34. patch: fwmark name-number translation table
4.36. Luca's php monitoring script
4.37. ipvsadm set option
4.38. ipvsadm error messages
4.39. ipvsadm fast update bug with smp
4.40. Problems when no scheduler
5.1. Introduction
5.2. LVS-NAT bugs
5.3. Example 1-NIC, 2 Network LVS-NAT (VIP and RIPs on different network)
5.4. All packets sent from the LVS-NAT realserver to the client must go through the LVS-NAT director
5.5. Run the configure script
5.6. Setting up demasquerading on the director; 2.4.x and 2.2.x
5.7. rewriting, re-mapping, translating ports with LVS-NAT
5.8. masquerade timeouts
5.9. Julian's step-by-step check of a L4 LVS-NAT setup
5.10. How LVS-NAT works
5.11. In LVS-NAT, how do packets get back to the client, or how does the director choose the VIP as the source_address for the outgoing packets?
5.12. One Network LVS-NAT
5.13. re-mapping ports, rewriting is slow for 2.0, 2.2 kernels
5.14. Two instances of demon running on realserver
5.15. Performance of LVS-NAT
5.16. Various debugging techniques for routes
5.17. Connecting directly from the client to a service:port on an LVS-NAT realserver
5.18. A NAT router has no connections
5.19. Thoughts on extending NAT
5.20. Postings from the mailing list
5.21. LVS-NAT source routing patch (Brownfield, Sawari and Black)
5.22. LVS-NAT FTP Recipe
5.23. LVS-NAT vhosts with apache
5.24. LVS-NAT timeout problem
6. LVS: The ARP Problem
6.1. The problem
6.2. Put the VIP on the realservers lo device
6.3. The Cure(s)
6.4. The Cure: 2.0 kernels - nothing needed
6.5. The Cure: 2.2.x kernels - many options
6.6. The Cure: 2.4.x kernels - arp_ignore/arp_announce
6.7. The Cure: 2.6.x kernels - arp_ignore/arp_announce
6.8. arptables
6.9. The arp problem is on the realserver's VIP not the RIP
6.10. Testing an interface for replies to arp requests
6.11. Normal machines, Solaris, Novell Server
6.12. problems with switches
6.13. The ARP problem, the first inklings
6.14. A posting to the mailinglist by Peter Kese explaining the "arp problem"
6.15. arp bouncing
6.16. Lar's Method
6.17. Static Routing to Director
6.18. iproute2 arp on|off flag
6.19. Is the arp behaviour of 2.2.x kernel a bug?
6.20. The device doesn't reply to arp requests, the kernel does.
6.21. Properties of devices for the VIP
6.22. Topologies for LVS-DR and LVS-Tun LVS's
6.23. Why do all devices broadcast the arp replies
6.24. A discussion about the arp problem
6.25. ATM/ethernet and router problems
6.26. Same IP on multiple NICs
7.1. LVS-DR example
7.2. How LVS-DR works
7.3. Handling the arp problem for LVS-DR
7.4. LVS-DR scales well
7.5. LVS-DR director as default gw for realservers, transparent proxy and Julian's martian and forward_shared patches
7.6. Accepting packets on LVS-DR director by fwmarks
7.7. security concerns: default gw(s) and routing with LVS-DR/LVS-Tun
7.8. routing to realserver from director
7.9. LVS-DR, LVS-Tun need rp_filter=0
7.10. Director as client in LVS-DR
7.11. from the mailing list
7.12. rewriting, re-mapping, translating ports with LVS-DR
8. LVS: LVS-Tun
8.1. LVS-Tun Intro
8.2. LVS-Tun example setup
8.3. You need a tunl0 device
8.4. the ARP problem with LVS-Tun
8.5. Reply packets appear to be spoofed
8.6. How LVS-Tun works
8.7. The RIP (not the tunl device) receives the ipip packet
8.8. Configure LVS-Tun
8.9. set rp_filter correctly
8.10. FreeBSD and Solaris realservers with LVS-Tun
8.11. Windows realservers with LVS-Tun
8.12. Realservers without ipip encapsulation
8.13. LVS-Tun has smaller MTUu: PMTU is disabled - handling fragmentation
8.14. MTU: early signs of problems
8.15. tunl mtu solved: Setting the MTU by MSS with iptables on the realserver
8.16. Setting the MTU by route
8.17. rewriting, re-mapping, translating ports with LVS-Tun
9. LVS: LocalNode
9.1. Two LocalNode Servers
9.2. Two Box LVS
9.3. Two Box LVS: both directors have active ipvsadm entries
9.4. Testing LocalNode
9.5. Localnode on the backup director
9.6. rewriting, re-mapping, translating ports with Localnode
10. LVS: You can't map (or rewrite) ports with LVS-DR, LVS-Tun or localnode (but you can with iptables)
10.1. You can't rewrite ports with localnode (but you can with iptables)
10.2. rewriting, re-mapping, translating ports with iptables in LVS-DR
10.3. can't port map with LVS
11. LVS: Non-LVS clients on Realservers
11.1. always NAT out clients through VIP
11.2. Masquerading clients on realservers to the outside world (SNAT)
11.3. Masquerading clients on LVS-NAT realservers
11.4. Masquerading clients on LVS-DR realservers
11.5. Masquerading clients on LVS-Tun realservers
11.6. Masquerading clients through the VIP on the director
11.7. 3-Tier LVS
11.8. Routes needed for 3-Tier LVS
11.9. Setting up routes using iptables and iproute2
11.10. from the mailing list
12. LVS: LVS clients on Realservers
12.1. Do you really need LVS clients on the realserver in a 3-Tier setup?
12.2. Realserver as LVS client in LVS-NAT
12.3. Realserver as LVS client in LVS-DR
12.4. Markus's thoughts
13. LVS: Non Linux Realservers
13.1. Loopback interface on Windows/Microsoft/NT/W2K
13.2. Windows Server 2008
13.3. Mac OS X (and Solaris)
13.4. Windows servers in Active Directory Domain
14. LVS: identd/authd
14.1. What is authd/identd?
14.2. authd/identd and other 3-Tier clients
14.3. symptoms of the identd problem
14.4. FAQ on identd
14.5. Russ Nelson on identd
14.6. Why identd is a problem for LVS
14.7. tcpdumps of connections delayed by identd
14.8. There are solutions to identd problem in some cases
14.9. Turn off tcpwrappers
14.10. using iptables to handle identd
14.11. Identd and smtp/pop/qmail
15. LVS: Variants on LVS: Local Nodes (One Box LVS)
16. LVS: Variants on LVS: Peter Warasin's ip_vs() in PREROUTING
17. LVS: Variants on LVS: Sven Ulland's Two-node setup with overlapping client subnets
18. LVS-J: Ludo's reinJect Forwarder: using the director as a gateway to load balance connections to the internet
18.1. Introduction
18.2. reinJect setup with ipvsadm
18.3. The target LVS: sending packets with dst_addr=0/0 to ip_vs
18.4. setting up LVS-J forwarding
18.5. SNAT'ing the output
18.6. LVS-J discussion by Ludo
19. LVS: Services: general, setup, debugging new services
19.1. Single port services are simple
19.2. setting up a (new) service
19.3. services must be setup for forwarding type
19.4. Realservers present the same content: Synchronising (filesharing) content and config files, backing up realservers
19.5. cfengine for synchronising files
19.6. File Systems for (really big) Clusters: Lustre, Panasas
19.7. File Systems for Clusters: Samba waits for a commit and is slow, NFS fills buffers and is fast
19.8. Discussion on distributed filesystems
19.9. load balancing and scheduling based on the content of the packet: Cookies, URL, file requested, session headers
19.10. Timeouts for TCP/UDP connections to services
19.11. name resolution on realservers: running name resolution friendly demons on realservers
19.12. Debugging new services
19.13. "broken" services:servlets and j2ee
19.14. http logs, error logs
20. LVS: Services: single-port
20.1. ftp, tcp 21
20.2. ssh, sftp, scp, tcp 22
20.3. telnet, tcp 23
20.4. smtp, tcp 25; pop3, tcp 110; imap tcp/udp 143 (imap2), 220(imap3). Also sendmail, qmail, postfix, and mailfarms.
20.5. Mail Farms
20.6. dns, tcp/udp 53 (and dhcpd server 67, dhcp client 68)
20.7. http name and IP-based (with LVS-DR or LVS-Tun), tcp 80
20.8. http with LVS-NAT
20.9. httpd is stateless and normally closes connections
20.10. netscape/database/tcpip persistence (keepalives)
20.11. dynamically generated images on web pages
20.12. http: sanity checks, shutting down, indexing programs (modifying /etc/hosts), htpasswd, apache proxy and reverse proxy to look at URL, mod_backhand, logging
20.13. HTTP 1.0 and 1.1 requests
20.14. Large HTTP /POST with LVS-Tun
20.15. http keepalive - effect on InActConn
20.16. Fallback/Sorry pages with Apache
20.17. Testing http with apachebench (ab)
20.18. Apache setup for DoS
20.19. squids, tcp 80, 3128
20.20. authd/identd, tcp 113 and tcpwrappers (tcpd)
20.21. ntp, udp 123
20.22. https, tcp 443
20.23. name based virtual hosts for https
20.24. Obtaining certificates for https
20.25. Self made certificates
20.26. SSL Accelerators and Load Balancers
20.27. SSL termination at localnode: patch by Carlos Lozano, Siim Poder and Malcolm Turnbull
20.28. r commands; rsh, rcpi (and their ssh replacements), tcp 514
20.29. lpd, tcp 515
20.30. Databases
20.31. Databases: mysql
20.32. Using Zope with databases
20.33. Databases: Microsoft SQL server, tcp 1433
20.34. Databases: Oracle
20.35. Databases: ldap, tcp/udp 389, tcp/udp 636
20.36. nfs, udp 2049
21. LVS: Services: multi-port
21.1. Introduction
21.2. ftp general, active tcp 20,21; passive 21,high_port
21.3. ftp helper modules: ip_vs_ftp/ip_masq_ftp
21.4. ftp (active) - the classic command line ftp
21.5. ftp (passive)
21.6. ftp helper bug(s)
21.7. ftp is difficult to secure
21.8. ftps (ssl based ftp), tcp 21, 22?
21.9. dns, tcp/udp 53 (and dhcpd server 67, dhcp client 68)
21.10. samba, udp 137, udp 138, tcp 139, tcp 445
21.11. xdmcp, X-window, udp 177 (xdmcp), tcp 6000 (and ssh X-forwarding)
21.12. r commands; rsh, rcp, and their ssh replacements, tcp 513 (,514) and another connection
21.13. Streaming Media: RealNetworks, Quicktime, Windows Media Server, tcp/udp 554 (and other ports)
21.14. Radius, udp 1645,1646
22. LVS: Services that we haven't got to work with LVS yet
22.1. Kerberos
22.2. RMI
23. LVS: UDP Services - unique problems
23.1. SIP (Session Initiation Protocol)
23.2. UDP timeouts (SIP)
23.3. UDP timeouts (DNS)
23.4. Julian's One Packet Scheduler (OPS) for UDP, timeouts for DNS
23.5. icmp responses aren't generated by UDP timeouts on VIP-less directors
24. LVS: Routing and packet delivery to a director without a VIP (for fwmark and transparent proxy)
24.1. Introduction
24.2. Routing to and accepting packets by a VIP-less director
24.3. Routing to the MAC address of the director
24.4. Julian's iproute2 solutions
24.5. Ludos LVS target in iptables
24.6. Transparent proxy Q and A
24.7. Other tricks
25. LVS: Fwmarks (firewall marks)
25.1. Introduction
25.2. ipvsadm syntax for fwmark
25.3. setting up routing and packet delivery to the director
25.4. single-port service: telnet with fwmarks
25.5. Grouping services: single group, active ftp(20,21)
25.6. Grouping services: two groups, active ftp(20,21) and e-commerce(80,443)
25.7. passive ftp
25.8. fwmark with LVS-NAT
25.9. collisions between fwmark and VIP rules
25.10. persistence granularity with fwmark
25.11. fwmark allows LVS-DR director to be default gw for realservers
25.12. fwmark simplifies configuration for large numbers of addresses
25.13. Example: firewall farm
25.14. Example: LVS'ing a CIDR block
25.15. Example: forwarding based on client source IP
25.16. Example: load balancing multiple class C networks
25.17. Example: proxy server
25.18. Example: transparent web cache
25.19. Example: Multiply-connected router
25.20. httpd clients (browsers)
25.21. Example: dynamically generated images in webpages
25.22. Example: Balancing many IPs/services as one block
25.23. Example: Source controlled LVS - services and realserver customised by Client IP
25.24. Appendix 1: Specificiations for grouping of services with fwmarks
25.25. Appendix 2: Demonstration of grouping services with fwmarks
25.26. Appendix 3: Announcement of grouping services with fwmarks
25.27. fwmark examples from the mailing list
26. LVS: Transparent proxy (TP or Horms' method)
26.1. setting up routing and packet delivery to the director
26.2. General
26.3. How you use TP
26.4. The original 2.2 TP setup method
26.5. Transparent proxy for 2.4.x (and presumably 2.6.x)
26.6. Experiments showing that 2.4TP is different to 2.2TP
26.7. What IP TP packets arriving on?
26.8. Take home lesson for setting up TP on realservers
26.9. Handling identd requests from 2.4.x LVS-DR realservers using TP
26.10. Performance of Transparent Proxy
26.11. The difference between REDIRECT and TPROXY
27. LVS: Transparent Bridging
28. LVS: Persistent Connection (Persistence, Affinity in cisco-speak)
28.1. LVS persistence
28.2. Scheduling looks different under persistence
28.3. Persistent and regular (non-persistent) services together on the same realserver.
28.4. Tracing connections: where will the client connect next?
28.5. Bringing down persistent services.
28.6. Forcing a break in a persistent connection: expire_quiescent_template - Horms sysctl for quiescing persistent connections
28.7. what if a realserver holding a persistent (sticky) connection crashes
28.8. Load Balancing time constant is longer with persistence
28.9. The tcp NONE flag
28.10. Resetting the persistence timeout counter (persistence behaviour for short timeout values)
28.11. Why you don't want persistence for your e-commerce site: why you should rewrite your application
28.12. more about e-commerce sites: we used to think memory was the problem - it isn't
28.13. persistence with windows realservers
28.14. messing with the ipvsadm table while your LVS is running
28.15. Persistence for multiport services
28.16. Proxy services, e.g. AOL
28.17. key exchanges (SSL)
28.18. About longer timeouts
28.19. passive ftp and persistence
28.20. The Persistence Template (about port 0)
28.21. persistent clients behind a proxy or nat box
28.22. Rogue clients hidden by persistence
28.23. Long (1 day) persistence to windows terminal servers
29. LVS: Running a firewall on the director: Interaction between LVS and netfilter (iptables).
29.1. Start with no filter rules
29.2. Introduction
29.3. Netfilter hooks and LVS: the path/route of an ip_vs controlled packet
29.4. how to filter with netfilter
29.5. ipvs_nfct, netfilter connection tracking for ipvs
29.6. LVS-NAT netfilter conntrack example with ftp
29.7. tcpdump is LVS compatible
29.8. Writing Filter Rules
29.9. The Antefacto Netfilter Connection Tracking patches
29.10. The design of LVS as a netfilter module, pt1
29.11. The design of LVS for Netfilter and Linux 2.4, pt2
29.12. Example ip_tables filter scripts
29.13. performance hit on director with iptables/netfilter
29.14. Long sessions through LVS DR director terminated by icmp-host-prohibited (ICMP type 3 code 10)
29.15. stateful filtering: LVS-NAT
29.16. stateful filtering: LVS-DR
30. LVS: Cluster friendly versions of applications that need to maintain state
30.1. rewriting your application/service
30.2. Session Data, maintaining state in a cluster, from Andreas Koening
30.3. Single Session
30.4. IIS session management: how it works
30.5. Maintaining state with persistence
30.6. How others maintain state
31. LVS: Squid Realservers (poor man's L7 switch)
31.1. Terminology
31.2. Preview
31.3. Let's start assembling
31.4. One squid
31.5. Another squid
31.6. Combining pieces with LVS
31.7. Problems
32. LVS: Performance and Kernel Tuning
32.1. Performance Articles
32.2. Estimating throughput: Rule of Thumb
32.3. Estimating throughput: 100Mbps FE is really 8000packets/sec ethernet
32.4. Jumbo frames
32.5. Network Latency
32.6. Mixture of 100Mbps and GigE ethernet
32.7. NICs and Switches, 100Mbps (FE) and 1Gbps (GigE)
32.8. Ethernet,NIC Bonding
32.9. NIC problems - eepro100
32.10. NIC problems - tulip
32.11. dual/quad ethernet cards, IRQ sharing problems
32.12. Flakey Switch
32.13. performance testing tools
32.14. Max number of realservers
32.15. FAQ: What is the minimum hardware requirements for a director
32.16. FAQ: How fast/big should my director be?
32.17. SMP doesn't help, but 64 bit does
32.18. Performance Hints from the Squid people
32.19. realservers filling conntrack tables (LVS-DR)
32.20. Conntrack, effect on throughput
32.21. Don't use the preemptible/preemptable/preemptive kernels
32.22. 9.6Gbps served using LVS-DR with gridftp
33. LVS: Monitoring
33.1. CPU usage/load level on the director?
33.2. LVS throughput at the director with ipvsadm
33.3. Monitoring: LVS director throughput statistics from the /proc system (originally /proc/net/ip_vs_stats)
33.4. MRTG family: Intro
33.5. MRTG family: LVSGSP
33.6. MRTG
33.7. MRTG family: RRDtool
33.8. MRTG family: cacti
33.9. MRTG family: Ganglia (incl. INSTALL)
33.10. MRTG family: rrd images
33.11. Nagios
33.12. MIB/SNMP
33.13. home brew MIB/SNMP
33.14. Disks
33.15. Other output GUIs
34. LVS: Details of LVS operation, Security, DoS
34.1. Top 20 security vunerabilities
34.2. Top 75 security tools from the people at nmap
34.3. Network Testing with Abberant Packets
34.4. Do I need security, really?
34.5. What to do after a break-in, prevention strategies
34.6. More about syncookies
34.7. Can filter rules stop the intruder hopping to other machines?
34.8. Where filter rules act
34.9. /proc filesystem flags for ipv4, e.g.rp_filter
34.10. tcp timeout values, don't change them (at least yet)
34.11. /proc file system settings for LVS: security and private copies of tcp timeouts for LVS connections (you can change these)
34.12. timeouts the same for all services
34.13. Director Connection Hash Table
34.14. Hash table connection timeouts
34.15. Hash Table DoS
34.16. Hash table size, director will crash when it runs out of memory.
34.17. The LVS code does not swap
34.18. Other factors determining the number of connections
34.19. Port range: limitations, expanding port range on directors
34.20. Director does not have any ports (connections) open for an LVS connection
34.21. apps starved for ports
34.22. realserver running out of ports
34.23. Maximum number of NICs
34.24. DoS
34.25. DoS, from the mailing list
34.26. Testing DoS Strategies with testlvs: Creating large numbers of InActConn
34.27. Debugging LVS
34.28. realserver content: filesystem or database? (the many reader, single writer problem)
34.29. Developement: Supporting IPSec on LVS
35.1. MTU discovery and ICMP handling
35.2. LVS code only needs to handle icmp redirects for LVS-NAT and not for LVS-DR and LVS-Tun
35.3. ICMP checksum errors
35.4. ICMP Timeouts
35.5. PMTUD (path MTU discovery)
35.6. Long sessions through LVS DR director terminated by icmp-host-prohibited (ICMP type 3 code 10)
36. LVS: High Availability, Failover protection
36.1. Introduction
36.2. Single Point of Failure (SPOF) - you can't protect against everything
36.3. Stateful Failover
36.4. Director failure
36.5. UltraMonkey and Linux-HA
36.6. Keepalived and Vrrpd
36.7. Using keepalived to failover routers
36.8. monitoring/failover messages should stay internal to LVS
36.9. Parsing problems with vrrpd config file
36.10. Two instances of vrrpd
36.11. HA MySQL
36.12. Failover of large numbers (say 1024) of VIPs
36.13. Some vrrpd setup instructions
36.14. Filter rules for vrrpd broadcasts
36.15. Vinnie's comparison between ldirectord/heartbeat and keepalived/vrrpd
36.16. Saru: All directors active at the same time
36.17. Active/Active by multipath: random musings
36.18. Server Load Balancing Registration Protocol
36.19. using iproute2 to keep demons running during failover, while link is down
37. LVS: Dynamic Routing, multiple gateways, realservers in multiple LVSs, dead gateway detection
37.1. Setting up multiple gateways: Realservers shared between two LVSs: ip route append
37.2. Connecting from clients through multiple parallel links: the dead gateway problem
37.3. Dynamic Routing to handle loss of routing in directors
37.4. Dynamic routing with gated: An LVS that connects to the outside world through two networks
37.5. flapping stemming from convergence time for spanning tree
38. LVS: Server State Sync Demon, syncd (saving the director's connection state on failover)
38.1. Intro
38.2. Release Notice
38.3. Expiration of Connection in Backup Director
38.4. Syncd boxes must have the same time
38.5. LVS and syncd do not use conntrack
38.6. Connection Synchronisation (TCP Fail-Over)
38.7. The synchd produces broadcast traffic
38.8. from the mailing list
38.9. Bug (fixed) in syncd: mixed endianness on directors
39. LVS: Realserver failure handled by Mon
39.1. Introduction
39.2. ethernet NIC failure, and channel bonding
39.3. Service/realserver failout: mon, ldirectord
39.4. Is ldirectord multithreaded? (ldirectord running high %CPU)
39.5. overriding ldirectord health checks from the command line
39.6. Mon for server/service failout
39.7. Monitoring the service running on the VIP on the realserver from the director
39.8. About Mon
39.9. Mon Install
39.10. Mon Configure
39.11. Testing mon without LVS
39.12. Can virtualserver.alert send commands to LVS?
39.13. Running mon with LVS
39.14. Why is the LVS monitored for failures/load by an external agent rather than by the kernel?
39.15. Running multiple directors (each with their own IP)
39.16. Mon scripts from Christopher DeMarco
40. LVS: Setting up Linux-HA for directors (mostly by using rpms)
40.1. linux-ha howto
40.2. Fix the (possible) ethernet alias issue.
40.3. Configure /etc/ha.d/. files.
40.4. Stop ldirectord from starting, ensure heartbeat starts on reboot
40.5. starting heartbeat and verifying functionality
40.6. Test your fail-over features, understand HA.
40.7. Configuration of mon - recommended
41. LVS: Director failover using heartbeat
41.1. Introduction
41.2. On using serial and ethernet connections for heartbeat
41.3. Ard van Breeman's replacement for IPaddr using ip and arping
42. LVS: Running LVS under UML (User Mode Linux), by Brett Elliot
42.1. Introduction
42.2. Ethernet bridging
42.3. Putting it all together: UML + LVS examples (not finished)
43. LVS: Newer networking tools: Policy Routing
43.1. Introduction
43.2. Policy Routing and ifconfig
43.3. Various debugging techniques for routes
43.4. checking source routed packets
43.5. handling arp problem with iproute2
43.6. ip commands you mightn't know about
43.7. Ratz's corrections on common iproute2/aliases misconceptions
43.8. Ratz's wrappers (for iproute2)
44. LVS: Weird hardware (and software)
44.1. Arp caching defeats Heartbeat switchover
44.2. Weird Hardware I: cisco catalyst routers gratuitously cache arp data (failover is slow)
44.3. Weird Hardware II: autonegotiation failure on cisco CSS 11050
44.4. Weird Hardware III: Watchguard firewall at client site
44.5. Weird Hardware IV: wrong device gets MAC address
44.6. Weird Hardware V: SonicWAll firewall rewriting sequence numbers
44.7. Weird Hardware VI: cisco 2924XL switch
44.8. Weird Hardware VII: unknown switches don't defragment
44.9. Weird Hardware VIII: bad routers/routing tables at ISP
44.10. Possible Wierd Hardware (or driver) IX: Broadcom GigE card
44.11. slow nics
44.12. PCI-X nics
44.13. Microsoft http clients and servers violate the RFC for TCP/IP
44.14. MSIE SSL bugs
45. LVS: Misc/FAQ/Wisdom from the mailing list
45.1. Having one director handling multiple LVS sites, Multiple VIPs
45.2. Setting up a fake service on the realserver with inetd
45.3. How to bring down a realserver for maintenance (eg swap disks)
45.4. keepalived: temporarily removing a realserver from view of keepalived; abnormal termination of keepalived
45.5. Howto turn your single node ftp/http server into an LVS without taking it off-line
45.6. shutdown of LVS
45.7. Other projects like LVS - Beowulf
45.8. Projects like LVS - Eddie
45.9. Recommendations for a redundant file system, RAID
45.10. on the need for extended testing
45.11. Bringing down aliased devices
45.12. Multiple IPs on the Director
45.13. Testimonials
45.14. Transport Layer Security(TLS)
45.15. Setting up a hot spare server
45.16. An LVS of LVSs
45.17. LVS on a Linux/IBM mainframe
45.18. mqseries
45.19. LVS log files
45.20. LVS and linux vlan
45.21. multi-home, multi-router LVS
45.22. Horror story, mostly from slow file system with disk intensive application
45.23. RTNETLINK answers:
45.24. LVS chokes on 600+ connections
45.25. Anti load balancing: all traffic required to go to one realserver
46. LVS: L7 Switching
46.1. Introduction
46.2. KTCPVS
46.3. DRWS
46.4. Alexandre's (unamed) L7 code
46.5. UltraMonkey-L7
46.6. from the mailing list about L7 switching
46.7. What is TCPSP?
47. LVS: Geographically distributed load balancing
47.1. Determining Location from the IP
47.2. Supersparrow
47.3. sharing/separate routers
47.4. Other uses of BGP4 with LVS
47.5. Geographically remote nodes connected by Bridging
47.6. Load Balancing by DNS (round robin DNS)
47.7. BIND, BGP with load balancing (more ideas from Horms)
47.8. Commercial Geographically Distributed Servers
47.9. from the mailing list
48. LVS: Loadbalancing with unmodified realservers
48.1. F5-SNAT
48.2. NetScaler
48.3. Using MASQ with REDIRECT to accept packet on realserver to replace a NetScaler
48.4. Using HAProxy with LVS to substitute for the remote server failover of a NetScaler
49. LVS: Virtualised Hosts in a Linux Virtual Server
49.1. Introduction
49.2. Virtualised Realsevers: VMWare/Xen
49.3. Running a test LVS (director, backup director and realservers) on one box (UML, VMWare)
49.4. VMWare problems with ntp
49.5. Xen tcpip checksum bug
49.6. Random observations thrashing around trying to get Xen/LVS-NAT working
50. LVS: Linux Distributions prepatched with LVS, Unsupported LVS addons
50.1. Distributions prepatched with LVS
50.2. PB's Nutshell HOWTO for Piranha/LVS-NAT
50.3. Horms advice for installing on RedHat systems
50.4. Recipe and LVS binaries for RedHat from Alex Kramarov
50.5. recipes for installing with RedHat from the mailing list
50.6. Hidden RPMs
51. LVS: Useful things that have no other place
51.1. Ramdisk
51.2. cscope
51.3. Neutral currents in multiphase power lines with non-linear loads (like computers with switching power supplies)
51.4. netcat/phatcat
52. LVS: FAQ
52.1. When will LVS be ported to Solaris, xxxBSD...?
52.2. Is there a HOWTO in Japanese, French, Italian, Mandarin...?