ICMP reply UUUUU

[ciscobond]

from my exchange i can telnet to isp server on port 25 bt not from ISP.i have firewall in between when i am pinging my public ip it is showing the following on my router which is on outside world on public IP's.other exchange servers are running fine

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 212.116.203.5, timeout is 2 seconds:
UUUUU
Success rate is 0 percent (0/5)

 

[fmonteiro]

The table below lists the possible output characters from the ping facility:

Character
Description

!
Each exclamation point indicates receipt of a reply

.
Each period indicates the network server timed out while waiting for a reply

U
A destination unreachable error PDU was received

Q
Source quench (destination too busy)

M
Could not fragment

?
Unknown packet type

&
Packet lifetime exceeded


This is a link to: Understand the Ping and Traceroute Commands:

http://www.cisco.com/warp/public/63/ping_traceroute.html

 

[gconnect]

that just means that you can't get to it and the router furthest in the chain doesn't have

'no ip unreachbles'
set on its interfaces

that router is just sending your router a msg that actually says "i can get to it"

if you were to traceroute it from a windows or *nix box that router would be displayed like

15.15.15.1 reports: destination unreachable


if they put the 'no ip unreachables' on their interface you would get the dots "....." instead