A cisco router broadcasts a gratuitous ARP response announcing to the world its IP address when it boots. See this example:
Ethernet Header Destination: FF:FF:FF:FF:FF:FF Ethernet Broadcast Source: 00:00:0C:3F:00:D4 Protocol Type: 0x0806 IP ARP ARP - Address Resolution Protocol Hardware: 1 Ethernet (10Mb) Protocol: 0x0800 IP Hardware Address Length:6 Protocol Address Length:4 Operation: 2 ARP Response Sender Hardware Address:00:00:0C:3F:00:D4 Sender Internet Address:172.16.10.1 Target Hardware Address:FF:FF:FF:FF:FF:FF Ethernet Broadcast Target Internet Address:172.16.10.1 Is your router not doing that for some reason? You could do some sniffing to see whether it does it. The gratuitous ARP should put the right ARP data into the 6509's ARP cache. So, I'm wondering if the ARP cache is the real problem. When you had the new router installed, what did "show int ethernet" display? Was it up/up? Can you send us some of your config for some more clues?? _______________________________ Priscilla Oppenheimer www.troubleshootingnetworks.com www.priscilla.com Mark Smith wrote: > > Unfortunately I don't have access to the 6509 or it would be a > done deal. My stuff's at a Sprint co-lo facility and getting > thru to a live tech across the country at Sprint is next to > impossible. The 6509 is theirs and is what I connect to on > their network to get out to the world. I was just looking for a > way to force their equipment to clear or refresh it's arp cache. > Thanks. > > Quoting Priscilla Oppenheimer : > > > Can't you just do a "clear arp" on the 6509? That's a > > commonly-used IOS > > command. I would assume it works on the 6509. Or > > should I say ass-u-me it > > works. :-) > > > > Priscilla > > > > Mark Smith wrote: > > > > > > I need to replace a router in a cabinet at the > > facility where > > > my hosted servers and equipment is. My equipment is > > "talking" > > > to the hosting facility's network via a port on a > > 6509 switch. > > > I replaced my router and then nothing from my > > network could > > > connect to the outside world. I waited about 2 > > minutes (during > > > which time my entire site's down and my bosses get > > VERY > > > nervous) and I never was able to connect from inside > > and my > > > tester on the outside was never able to get in to > > me. I finally > > > put router #1 back in and all was well again. I've > > scoured the > > > configuration and #2's is identical with #1 so I > > don't believe > > > that is the problem. I'm ass-u-me-ing that the > > reason for this > > > is the 6509 port's ARP cache is looking for the MAC > > address of > > > router #1 and it ain't there anymore. Would this > > ass-u-me-ption > > > be correct or is it possibly something else I'm not > > > thinking/aware of? If it is an ARP issue, is there a > > way that I > > > can remotely force the 6509 port to > > reset/clear/refresh it's > > > ARP cache? I'm at a Sprint facility and I'd sooner > > get a live > > > body (that's not a first level phone answerer > > anyway) to talk > > > to me when I'm calling Mars than trying to get one > > at Sprint. > > > > > > Any ideas/thoughts/chastisements on missing the > > obvious here? > > > As much as I'd like to work with Cisco gear full > > time, it's > > > only a very small part of my current job and, > > consequently, due > > > to my lack of familiarity with what you guys do all > > day every > > > day, it's very likely that I'm missing something > > that all in > > > the world except me know about. > > > Thanks for any help or ideas. > > > > > > Mark > > [EMAIL PROTECTED] > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=56710&t=56680 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
