in our datacenter we are using two 3750G stack as L2 core switches; in the last year we're suffering a strange problem: we're seeing unicast traffic spread over all trunk ports (basically all the uplink to the satellite switches). In the beginning we thougth it was an unicast flooding, but latest test show that:
- access ports are not affected by this issue: if we connect a sniffer to a port in access (not in span) we are seeing only normal traffic (broadcast/multicast)
- trunk ports are affected by this issue: if we connect a sniffer to a port in trunk (not in span) we are seeing unicast traffic!
- during the issues the mac address table is not full
- it seems that if we restrict the number of vlan on the trunk (e.g. 1-100) we're seeing odd traffic but only of the allowed vlan (no inter vlan flooding)
Can anyone give us a suggestion? We thougth it was an IOS bug and this summer we upgrading the IOS to the 12.2 (55) version
yes vtp pruning is enabled everywhere, but we think it's not working properly. The next step we planned is enabling manually only the useful vlan on every trunk (at the moment all the vlan are allowed on every trunk).
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...