Jan� van Deventer wrote: > > > At 11:05 PM 6/30/2003 +0000, Shibu Nair wrote: > > >Hi > > > > > >Can somebody let me know what exact keyword (not icmp type > > number) should > > >be used > > >to enable the incoming access-list for trace route unix > > application to work > > >fine... > > > > > >I know UDP should be allowed for outgoing and ICMP should be > > allowed for > > >the incoming... > > I read once that Cisco routers use a different way to do > traceroute than Windows PCs. Does anybody know what this > difference is?
Both Cisco and Unix send a UDP packet to a high UDP port number, >33,000. Windows sends a ping packet. But the important part works the same regardless. They both manipulate the IP TTL field and expect to get ICMP TTL exceeded packets back from routers. With the UDP method you should also get back a Destination Unreachable (Port unreachable) from the end host. With the ping method, you should just get back a ping reply. Thanks for "quoting!" :-) Priscilla > > Regards, > Jan� Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=71763&t=71697 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
