> -----Original Message----- > From: Stefan Fouant [mailto:sfou...@shortestpathfirst.net] > Sent: Sunday, March 07, 2010 8:04 AM > To: Eric Van Tol; juniper-nsp-boun...@puck.nether.net; Derick Winkworth; > Juniper-Nsp > Subject: Re: [j-nsp] Strange IS-IS Problem > > I could be wrong but if I recall correctly the Hello PDU uses a padding > TLV to pad the initial hello to the maximum MTU size. I don't believe > these packets are fragmentable if I recall considering it's a CLNS frame, > i.e. no IP header and thus no fragment options. I think it's already been > said but the fact that you are using jumbo frames and also because you are > using EX 2500s (not native JUNOS) makes it extremely suspect that you are > likely running into some form of MTU issue.
But if I can push through a baby giant packet without even configuring anything, wouldn't that mean that large packets are allowed through? > One other thing you might want to check on the EX 2500 - interface > counters - look for L2 Channel errors or other inconsistencies which might > indicate the EX doesn't recognize the Ethertype, etc. I checked the various counter stats and could not find any errors on any of the ports. In fact, I see this: Received valid L2 unicast packets: 18473 Received valid IPv4 unicast packets: 18473 Received valid L2 multicast packets: 123024 Received valid non-IP multicast packets: 123000 Received valid IPv4 multicast packets: 24 Received 64 byte packets: 23 Received 65-127 byte packets: 123032 Received 128-255 byte packets: 1 Received 1024-1522 byte packets: 8393 Received 1523-2047 byte packets: 10048 Received octets: 48192973 Received octets in valid non-IP packets: 15127879 Received octets in valid IPv4 packets: 33065094 As an aside, it appears that OSPF works fine if I set that up. Not a long term solution, though. I do believe that you are on to something, though. Unfortunately, I can't see anywhere to configure the EX2500 ports to accept specific ethertypes. Does anyone else have ISIS running _through_ an EX2500? > Stefan Fouant -evt > ------Original Message------ > From: Eric Van Tol > Sender: juniper-nsp-boun...@puck.nether.net > To: Derick Winkworth > To: Juniper-Nsp > Subject: Re: [j-nsp] Strange IS-IS Problem > Sent: Mar 7, 2010 4:42 AM > > > From: Derick Winkworth [mailto:dwinkwo...@att.net] > > Sent: Sunday, March 07, 2010 1:26 AM > > To: Eric Van Tol; Juniper-Nsp > > Subject: Re: [j-nsp] Strange IS-IS Problem > > > > If its JUNOS, then just configure the MTU normally in the interface > > config on the switch. > > It does not run JUNOS and there is no config option for MTU that I can > find. I don't believe that it's configurable, but it "just works". > Without configuring anything on the EX2500, I was able to pass 2000-byte > sized IP packets between the Junipers. > > -evt > > > > _______________________________________________ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp > > > Sent from my Verizon Wireless BlackBerry _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
