Clearing the arp file

[theletterz]

I just replaced two servers which were behind the CSS LAN with two brand new ones. The old servers were never actually in use, but services and content rules were created.

I entered the same private IP addresses for the new servers, 192.168.1.11 and *.12, but the CSS and the servers can't see each other, and when I look in the ARP table, I see that both IP addresses has the MAC addresses of the old servers which I assume is why (the servers can see any other server on the CSS LAN).

I can't get rid of them by typing clear arp cache <ip address>, and I see that these entries are also in the arp file.

The CSS has been rebooted in the meantime and it's actually close to two months ago since I disconnected the old servers from the network, so I cannot figure out why these entries stay.

Question is, will clear arp file get rid of these entries? If I clear the arp file (as far as I can see from the documentation I can't clear single entries in the arp file), will this disturb connectivity and services to other boxes?

[Gilles Dufour]

there is no arp file on the CSS.

If after a reboot the CSS learns those mac addresses again it means there is a device in your network with this mac address and it is responding to arp request for these ip addresses.

IF you really don't think so, put a sniffer on the vlan and do a clear arp - verify the sniffer for arp request/response.

Do the same for a reboot.

Gilles.

[theletterz]

Erm, okay, why do I get this response, then:

PROD2-CSS-B# sh arp file

192.168.1.7

192.168.1.13

192.168.1.5

192.168.1.9

192.168.1.6

192.168.1.14

192.168.1.8

172.255.7.253

192.168.1.10

192.168.1.11

192.168.1.12

And why does it in the Cisco Content Services Switch

Routing and Bridging Configuration Guide (7.40) in chapter 4.5 say among several things this:

"Updating ARP Parameters

To update the file containing hosts reachable through ARP, use the update arp command. This command is available only in SuperUser mode.

For example:

# update arp file"

[Gilles Dufour]

my sincere apologies - In 4 years playing with the CSS I never encounter those functions/commands.

So after a little research into the code, I found out that we indeed have an ARP file called arp.txt

You can delete it manually if you want

llama

ap_file delete c:/sg0740113s/info/arp.txt

Replace the version that you see in the example above by yours.

Again sorry for the initial error and thanks for having taught me something :-)

G.

[theletterz]

No problem. :-)

Still you were correct, the old servers are broadcasting the MAC address of their disconnected interfaces via their primary interface.

I used ethereal and sniffed traffic, and immediatly after the new servers broadcast their ARP response, the response from the old servers arrives at the CSS.

Thanks, I'll disable their disconnected interfaces completely tonight and see if this fixes everything.