IN the Redhat 5.3 distribution when you bring upo the ping man page you get a concatenation of ping and ping6. It implies that the syntax of

ping -I <interface name> <IPv6 address to be pinged>

the above command fails with a "unknown host" message. this occurs with a link local as well as a global address.

[jtr@LinuxServer-1 ~]$ ping -I eth1 3001:2234:1122:301:20c:29ff:fe41:a733
ping: unknown host 3001:2234:1122:301:20c:29ff:fe41:a733
[jtr@LinuxServer-1 ~]$

[jtr@Linux-1 ~]$ ping6 -I eth1 3001:2234:1122:301:20c:29ff:fe41:a733
PING 3001:2234:1122:301:20c:29ff:fe41:a733(3001:2234:1122:301:20c:29ff:fe41:a733) from 3001:2234:1122:101:20c:29ff:fe93:cb27 eth1: 56 data bytes
64 bytes from 3001:2234:1122:301:20c:29ff:fe41:a733: icmp_seq=0 ttl=126 time=4.23 ms

ping fails but ping6 works just fine. I use ping6 but I have been asked to research this.

My beleif is that the man page for ping/ping6 should have one more sentence added for the -I switch that states "the -I option is only for ping6 and ping does not work for IPv6 addresses.


do you think that this is a valid assumption about ping. All of the research I have done on this always indicate to use the ping6 command.

the same thing occurs being logged in as root or a regular user.


regards

Jerry

http://tldp.org/HOWTO/html_single/Li...-HOWTO/#AEN811

IIRC: the command you are looking for is ping6.

If ping fails and ping6 works then it is network blocked or firewall issue or routing issue.

man ping

Simon,

It appears based on what you are saying and my other research "ping" by itself does not work in Linux for V6 addresses. I can do anything I need with the "ping6" command in the V6 space. the MAN page is misleading for the -I switch or incomplete probably a better way to word it.

do you concure?

Jerry

Jefro,

I do not think this has anything to do with a firewall. It more resembles a name resolution issue than anything based on the error shown above "ping: unknown host 3001:2234:1122:301:20c:29ff:fe41:a733".

regards

Jerry