VPN and TTL values

[kevmullet]

Hi,

I don't know if anyone else is curious about this but i am very confused. basically i have two LANs linked by a VPN (Zywall 35 to Zywall 35) and pinging across the link is fine.

If i ping the remote Zywall LAN address i get a response with a TTL of 253

If i ping a machine on the remote LAN i get a response with a TTL of 128

If i ping a phone system attached to teh remote LAN i get a response with a TTL of 28

Can anyone explain why the drastic differences in TTL's especially the difference in what is basically two hosts on the remote network.

Thanks

 

[brainpk]

TTL is dependent on the host you are pinging, and has nothing to do with the Medium (VPN in your case). Differnet machines have different TTLs, for example new Microsoft machines have TTL 128, routers normally have 254, old machines have 32 and so on. You can check TTL of your local machine by ping localhost. You can also control TTL with -i flag in ping command.