RE: 3550 COnnectivity

From: Mike Calhoon (mcalhoon27@earthlink.net)
Date: Sat Jul 17 2004 - 19:44:08 GMT-3


Ken,

 

  I thought it had something to do with proxy-arp. You are right about the
arp table. Before I put in the default-gateway command the destination IP
showed up in the arp table, but did not after the command was entered. The
thing about my setup is there are two possible gateways on the VLAN. I
suppose it shouldn't matter which one it uses though, but I guess I didn't
feel like choosing. Here are the outputs...

 

SW1 is on VLAN62...ip address is 168.1.62.7.

 

Before default-gateway...

 

Rack1SW1#ping 168.1.4.4

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 168.1.4.4, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 116/316/1116 ms

Rack1SW1#show arp

Protocol Address Age (min) Hardware Addr Type Interface

Internet 168.1.4.4 0 0010.7b7f.1202 ARPA Vlan62

Internet 168.1.62.7 - 000a.8a9a.2800 ARPA Vlan62

 

After a clear arp and default-gateway to 168.1.62.2

 

Rack1SW1#ping 168.1.4.4

 

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 168.1.4.4, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 116/316/1116 ms

Rack1SW1#show arp

Protocol Address Age (min) Hardware Addr Type Interface

Internet 168.1.62.7 - 000a.8a9a.2800 ARPA Vlan62

Internet 168.1.62.2 0 0010.7b7f.1202 ARPA Vlan62

 

 

   Thanks,

     Mike

 

 

 

  _____

From: Kenneth Wygand [mailto:KWygand@customonline.com]
Sent: Saturday, July 17, 2004 6:23 PM
To: Mike Calhoon; Lord, Chris; ccielab@groupstudy.com
Subject: RE: 3550 COnnectivity

 

Mike,

Without specifying the "ip default-gateway", your 3550 will default to using
proxy-arp to resolve your IP addresses to MAC addresses. If your attached
router (on the VLAN where your switch's IP address is) supports proxy-arp,
it will resolve and your ping will succeed.

 

You should have entries if you do a "show arp" when using proxy-arp, but I
don't believe those entries will exist when crossing VLANs if you have a
default gateway configured (just your default gateway will be in your local
arp table).

 

If you can, try it out both ways and post your outputs! :)

 

Hope this helps,

Ken

[GroupStudy removed an attachment of type application/ms-tnef which had a name of winmail.dat]



This archive was generated by hypermail 2.1.4 : Sun Aug 01 2004 - 10:11:57 GMT-3