ping

[Tammy Liang]

I can telnet to a hp-ux 10.20 system, but not
able to ping the same system.

Appreciate any help...

[Steven E. Protter]

It is possible with ip filter on HP-UX or any commerical firewall to disable ping, ICMP but still alllow for telnet.

ping was used for the DOS(denial of service) attack on the major web sites a few months ago, and is often disabled in many environments.

The current Blaster virus also pumps network traffic through the roof, causing inadvertant DOS attacks and many admins are turning off ping to combat it.

SEP

[D Block 2]

Try ping in reserve mode. Telnet to hp-ux system, then ping yourself/cleint system. I agree, some corporate networks turn off ICMP (or PING) service.

before you think its a network issue, try running Ping to www.sun.com. You should most always get a Ping response from Sun.

another useful tool at times is TraceRoute. NT Dos Cmd: TRACERT

[E. Wong]

Don't get suprised if you cannot ping to the same host you can telnet to. Most firewalls block ICMP ping to avoid DOS attacks.

Remember that ping can only get you to the lowest level of the OSI layers. Telnet works on the network layer which is higher.

[twang]

Yes, it is very common that firewalls block icmp (ping signal) to avoid being attacked.

[zanwar.prashantuktransc]

Please check if your Server is advertising Default route or not!!

[zanwar.prashantuktransc]

Please check if your Server is advertising Default route or not!!


Regards
Prashant