User A was moved to a over to a VLAN on our network yesterday, which contains (6) 2950 switches trunked together via the GigabitEthernet ports, routing through a 2801, through a firewall, to a 2600 router and out to the Internet now he's having problems sending E-mail's with attachments larger than 40K. User A can get to the internet fine and use e-mail without attachments, but when sending e-mails with attachments, whether the service is web-based or POP3, the SMTP message time's out.
When User A is on the native VLAN he has no problems with E-mail attachments. MTU on both the router and firewall are at default 1500. Even if it was a MTU issue, which I don't think it is, that would effect the native VLAN users as well, or so I would think. Could this be an MSS problem?
We're using an Internet Web Filter so we do use SPAN to monitor ports
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...