I've a micro-LAN consisting of two computers, I'll call the one connected to both the internet and the LAN the primary, and the other, using the primary as a proxy, will be the secondary.
Does there exist a utility that can tell me for certain what the TTL property of the packets leaving the primary to the internet are set for?
I would like to be stealth about using firefox on the secondary as well as the primary as far as anyone external, including my ISP, is concerned. If there is such a utility, I could see for certain that the TTL settings are the same leaving the primary for the internet, and the ISP, whether I'm using Firefox on the secondary or the primary.
Conceptually, my thought was that increasing the TTL on the packets leaving the secondary to the primary by one would take care of this (using POSTROUTING in the iptables of the secondary to "mangle" the TTL, or PREROUTING in the iptables of the primary). But complexity is added because I've got Squid configured on the secondary, I'm not absolutely sure that web traffic coming from Firefox on both machines is treated the same, and, while both machines are running Fedora 8, one is i686 and the other x86_64 and I can't be totally sure that the default TTL is the same on both of them.
If I could make a comparison of the TTLs leaving the primary for the net, based upon which machine is surfing the net, It would give peace of mind that adjustments are correct.
Or, I could just set everything leaving the primary to a set TTL, but aren't there circumstances where a TTL should not be touched?