Re: VMAC, vmac_xmit_base, and IGMP
Alexandre Cassen <[email protected]>
| Newsgroups | gmane.linux.keepalived.devel |
|---|---|
| Message-ID | <[email protected]> |
Hi Patrick, Well, some switch are updating their CAM according to IGMP join msg (cisco are doing it), so if you are using switch like that vmac_xmit_base must be used. regs, Alexandre On 27 May 2014, at 17:44, Patrick Schaaf <[email protected]> wrote: > Hi, > > "playing" with the VMAC feature on a keepalived 1.2.13 driven cluster of > balancers, I noticed a peculiar "feature" that I saw no mention of in the > documentation. Thought I'd note it here... > > I am running a ping to the VRRP address from an internal host. Then I restart > one of the BACKUP keepaliveds. And notice a single ping to receive an "ICMP > host unreachable" reply with source the IP address of that BACKUP balancer. > > Looking into it with tcpdump, I notice that when the daemon starts, it sends > IGMP messages with source MAC the VMAC - thus teaching the switch, for a short > while, that it would like to have packets for the VMAC. > > Adding vmac_xmit_base to the configuration fixes the issue - the IGMP messages > are then sent with the base interface source MAC address. > > In practise the "error interval" will probably be smaller, due to the MASTER > balancer more continuously sending packets with VMAC source - my test setup > has no operational traffic or I probably wouldn't have noticed. > > I don't know whether this could be considered a bug, or at what priority, or > what to do about it, except maybe adding another reason in the docs why > vmac_xmit_base might be a good idea. > > I'll close with a curious question: are there reasons why vmac_xmit_base is > NOT a good idea? > > best regards > Patrick > > ------------------------------------------------------------------------------ > The best possible search technologies are now affordable for all companies. > Download your FREE open source Enterprise Search Engine today! > Our experts will assist you in its installation for $59/mo, no commitment. > Test it for FREE on our Cloud platform anytime! > http://pubads.g.doubleclick.net/gampad/clk?id=145328191&iu=/4140/ostg.clktrk > _______________________________________________ > Keepalived-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/keepalived-devel ------------------------------------------------------------------------------ HPCC Systems Open Source Big Data Platform from LexisNexis Risk Solutions Find What Matters Most in Your Big Data with HPCC Systems Open Source. Fast. Scalable. Simple. Ideal for Dirty Data. Leverages Graph Analysis for Fast Processing & Easy Data Exploration http://p.sf.net/sfu/hpccsystems