[Info-vax] PEA0: Errors

[JF Mezei]

Christoph Gartmann wrote:

> Yes, the switch tells something about excessive collisions and drop rates.

For full duplex links, you shouldn't have collisions. Are you sure both
sides of each link (switch and computer) have proper settings or auto
negotiation ?

Note that for half duplex links on switches, having collisions is
normal. It just means that the switch detected the link being used in
the other direction before attempting to send a packet, so it delayed
that packet (and increased the collision number).

> Meanwhile I think I found the reason: the packet sniffer shows that it is an
> antispam box that produces huge amounts of illegal tcp sequence numbers every
> 37 minutes so that the switch gets overwhelmed :-( This box communicates
> with one of the cluster members in order to deliver mail.

Depending on the sophistication level of your switch, you could possibly
give SCS traffic greater priority than IP traffic, in which case, that
IP box's tamper tantrum wouldn't prevent SCS traffic from being delivered.