Re: [LARTC] IP Failover
If anyone is interested, in my quest for a networking solution which provides IP Failover on heterogenous redundant networks, I have listed the solutions I found below. I would welcome comments from anyone who is familiar with these. faild - I have included a description below of a program daemon which monitors the Ethernet connections and changes the routing tables when a failure is detected. IP Failover is all this simple program does. Being simple, however, makes it small and easy to port. High Availability Linux Project (HAL) (http://linux-ha.org/) has code available for FreeBsd and Solaris (and probably reasonably portably to other UNIX platforms. It supports virtual (redundant) servers but could probably therefore be configured to support redundant LANs. Advanced Network Services (ANS 2.3.x) for Linux* Operating Systems. which is available from Intel on both PCs and UNIX OS's. ANS provides IP Failover and much more, such as switch failover, load leveling, etc. See: http://www.intel.com/support/network/adapter/onlineguide/PRO1000/DOCS/SERVER/index.htm. Linux Virtual Server Project (LVS) - VRRPD, Virtual Router Redundancy Protocol (http://off.net/~jme/vrrpd/) which also provides IP Failover. It implements RFC2338 but is only available on Linux but may be portable. As with HAL, it is probably configureable to provide redundant LAN. It seems the days of industry-wide standards and interoperability are becoming casualties of war. John Klingler Automatic IP Failover: faild Figure 1 shows a typical redundant network configuration where all nodes are connected to two, separate Ethernet LANs (here referred to as Ethernet A and Ethernet B). Each node must have two Ethernet interfaces, one for each LAN. Distinct IP addresses are assigned to all Ethernet interfaces. _ . . . | | Host 1 Host 2 | __|__ . . . Figure 1: Typical Redundant Network Configuration A route monitor daemon is started on all nodes. Each daemon is configured to be either a responder or both a requestor and responder. Typically the host daemons are requestor/responders. Requestor daemons broadcast inquiry (INQ) packets on all available networks at a specified interval. Upon receiving an INQ each responder daemon sends back an acknowledgment (ACK) via the same route. These packets are all sent using UDP (Unreliable Datagram Protocol) so the daemons can quickly detect if a route is active. If the requestor daemon does not get ACKs from a given node and if the responder daemon does not get INQs as expected, then each daemon independently determines that the particular route has become unreliable, or more likely, has gone dead. Each daemon then changes its local system routing tables so future traffic will be routed over the alternate (and presumably healthy) LAN. This detection and failover occurs very quickly, in a matter of a few seconds, depending on how the daemon's timing parameters are set. When a route fails, network traffic carried by reliable protocols (such as X Window traffic via TCP -- Transmission Control Protocol) is held in abeyance until the IP stack recognizes that packets are not getting through. When the IP stack times out packets waiting for delivery will be retransmitted. Since the daemon has changed the routing tables the retransmitted packets will go via the new route. The IP time-out time is the critical parameter determining how long it will take from initial route failure to establishing communication over the new route. This parameter may or may not be user-settable on your system. Field experience so far indicates lag times of 20-40 seconds before communication resumes. As soon as the original route becomes reliable again, the daemon will restore the routing tables and communication resumes over the original interface. There should be no noticeable delay on the switchback. Request packet interval, failover interval, and switchback interval are all configurable. To initiate a failover daemon on your host system, use the following convention: faild [-r] [-t n] [-f n] [-s n] [-p n] [-l p] -r should launch requestor -t n : timer interval (in secs) for sending of pkts -f n : num missed pkts before if is invalidated -s n : num good pkts before if is revalidated -p n : port number to use -l p : full path to message log file Note: This daemon currently runs on VxWorks, Digital UNIX and Solaris, and is being ported to OpenVMS. Any other platforms would require porting the daemon to the target OS.
Re: [LARTC] IP Failover
On Tuesday 07 October 2003 21:55, John Klingler wrote: If anyone is interested, in my quest for a networking solution which provides IP Failover on heterogenous redundant networks, I have listed the solutions I found below. I would welcome comments from anyone who is familiar with these. 1. faild - I have included a description below of a program daemon which monitors the Ethernet connections and changes the routing tables when a failure is detected. IP Failover is all this simple program does. Being simple, however, makes it small and easy to port. 2. High Availability Linux Project (HAL) (http://linux-ha.org/) has code available for FreeBsd and Solaris (and probably reasonably portably to other UNIX platforms. It supports virtual (redundant) servers but could probably therefore be configured to support redundant LANs. 3. Advanced Network Services (ANS 2.3.x) for Linux* Operating Systems. which is available from Intel on both PCs and UNIX OS's. ANS provides IP Failover and much more, such as switch failover, load leveling, etc. See: http://www.intel.com/support/network/adapter/onlineguide/PRO1000/DOCS/SERVE R/index.htm. 4. Linux Virtual Server Project (LVS) - VRRPD, Virtual Router Redundancy Protocol (http://off.net/~jme/vrrpd/) which also provides IP Failover. It implements RFC2338 but is only available on Linux but may be portable. As with HAL, it is probably configureable to provide redundant LAN. If I was you, I should go for keepalived. This is part of LVS but you can also use it just for the ip Failover. Companies like IBM, RH, are using this so I think it can be trusted. http://freshmeat.net/projects/keepalived/ In addition, it implements a VRRPv2 stack to handle director failover. Stef -- [EMAIL PROTECTED] Using Linux as bandwidth manager http://www.docum.org/ #lartc @ irc.openprojects.net ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
RE: [LARTC] IP Failover
This would make greater sense/benefit/appropriateness on two different machines, I think. vrrpd is another good alternative. sourceforge is the repository. In some cases, a filer for exemple, you just want to have two of it's NICs connected to two different switches. Then you dont loose the filer when a switch burns or a cable is cut. Rgds, Ronnie. ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
Re: [LARTC] IP Failover
On Tuesday, 30 September 2003, at 08:40:12 +0300, Andrew Kozachenko wrote: !DOCTYPE html PUBLIC -//W3C//DTD HTML 4.01 Transitional//EN Ugh !. Please configure your mail client to send outgoing messages only in plain text, preferably wrapped at 75 characters or less. Thank you. -- Jose Luis Domingo Lopez Linux Registered User #189436 Debian Linux Sid (Linux 2.6.0-test5-mm3) ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
[LARTC] IP Failover
Does anyone know of a system service that will provide automatic IP failover on a system with dual (redudnant) Ethernet adapters? For example, I can simulate this by manually deactivating eth0 and activating eth1, although it takes about 15 secs for the MAC address to be updated. It should be relatively simple to write a program that monitors the current Ethernet interface and does the change-over automatically (and forces the MAC update), but before re-inventing the wheel, I suspect there is already a system program that already does this, I just haven't found one on Red Hat 8.0. thanks in advance, --John Klingler ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
Re: [LARTC] IP Failover
there are several; http://www.linux-ha.org/ is a good place to start. On Mon, 2003-09-29 at 10:36, John Klingler wrote: Does anyone know of a system service that will provide automatic IP failover on a system with dual (redudnant) Ethernet adapters? For example, I can simulate this by manually deactivating eth0 and activating eth1, although it takes about 15 secs for the MAC address to be updated. It should be relatively simple to write a program that monitors the current Ethernet interface and does the change-over automatically (and forces the MAC update), but before re-inventing the wheel, I suspect there is already a system program that already does this, I just haven't found one on Red Hat 8.0. thanks in advance, --John Klingler ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
RE: [LARTC] IP Failover
This would make greater sense/benefit/appropriateness on two different machines, I think. vrrpd is another good alternative. sourceforge is the repository. Regards Mohan -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Ben Sent: Monday, September 29, 2003 11:12 PM To: [EMAIL PROTECTED] Subject: Re: [LARTC] IP Failover there are several; http://www.linux-ha.org/ is a good place to start. On Mon, 2003-09-29 at 10:36, John Klingler wrote: Does anyone know of a system service that will provide automatic IP failover on a system with dual (redudnant) Ethernet adapters? For example, I can simulate this by manually deactivating eth0 and activating eth1, although it takes about 15 secs for the MAC address to be updated. It should be relatively simple to write a program that monitors the current Ethernet interface and does the change-over automatically (and forces the MAC update), but before re-inventing the wheel, I suspect there is already a system program that already does this, I just haven't found one on Red Hat 8.0. thanks in advance, --John Klingler ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
Re: [LARTC] IP Failover
S Mohan wrote: This would make greater sense/benefit/appropriateness on two different machines, I think. vrrpd is another good alternative. sourceforge is the repository. vvrpd was designed just "to prove the concept" and is not recommended in production environment. keepalived (http://keepalived.sourceforge.net/) works great for me. Regards Mohan -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Ben Sent: Monday, September 29, 2003 11:12 PM To: [EMAIL PROTECTED] Subject: Re: [LARTC] IP Failover there are several; http://www.linux-ha.org/ is a good place to start. On Mon, 2003-09-29 at 10:36, John Klingler wrote: Does anyone know of a system service that will provide automatic IP failover on a system with dual (redudnant) Ethernet adapters? For example, I can simulate this by manually deactivating eth0 and activating eth1, although it takes about 15 secs for the MAC address to be updated. It should be relatively simple to write a program that monitors the current Ethernet interface and does the change-over automatically (and forces the MAC update), but before re-inventing the wheel, I suspect there is already a system program that already does this, I just haven't found one on Red Hat 8.0. thanks in advance, --John Klingler ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ -- Regards, Andrew Kozachenko Entri ltd. _ / \ | If you ever know the power of the dark side... | \_/ ___ LARTC mailing list / [EMAIL PROTECTED] http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
