[c-nsp] Cursed IP address

[Victor Sudakov]

Daniel Roesen wrote:
> On Sat, Nov 29, 2014 at 09:41:45PM +0600, Victor Sudakov wrote:
> > We have set up port monitor sessions in various parts of the network
> > and have found out the following. One of the C3560X-24P in the chain
> > of identical switches does not let through packets with
> > src=10.65.127.246&dst=224.0.0.5. Neither when such packets transit the
> > switch nor when it's configured on one of it's own Vlan interfaces.
> > 
> > Other switches in the chain are identical from the hardware/software
> > point of view, and configured almost identically, but do not suffer
> > from the problem.
> 
> Check for enabled IGMP snooping on this switch. Try disabling snooping.

We have already tried that, with no effect. Besides, IGMP snooping
should not affect packets with only one unicast source address on only
one switch.

> Wouldn't outrule broken hardware... Some bit flip error or so.

We may try to change the hardware some day, but for the present it's
easier to just avoid one particular IP address.

-- 
Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
sip:sudakov at sibptus.tomsk.ru