HP-UX is very sensible on netmask setting which you have not said anything...
next, the configuration of the network port HAS TO MATCH with the port of your switch or you are also in trouble...
FORGET USING MOZILLA TILL YOU HAVE SOLVE YOUR NETWORK ISSUE otherwise you take the risk of misconfiguring something that will generate unsolvable issues, and your are to restart the installation again from scratch, discipline and method is VERY important to achieve a wealthy install...
You still have not said with what you edit your system files... HP-UX can be corrupted if you use anythng else than vi!
You havent answered what were the init like, is all that is started successful?
How did you configure your network (using what tool?), thats a few years I have not touched an HP but remember if my memory serves me a tool called setparms or something of the sort, if I told you to avoid DHCP there was a reason:
IF YOU HAVE NOT CONFIGURED CORRECTLY YOU NETWORK BEFORE, YOU HAVE A SYSTEM THAT WILL ALMOST NEVER WORK UNLESS YOU KNOW HP-UX IF YOU HAPPEN TO TOUCH DHCP...
Worse would be to plug the system to a network when installing letting the system find out by himself, same result if you are on a badly configured network, unless you know well HP-UX you can restart you install and dont do the same mistake again
Why?
Because you machine will ask the network who he is, and what will the network answer?
If you are lucky the netwrk replies "unknown" and your box will continue the confuguration giving unknown as hostname, then what will be the IP when asking for UNKNOWN ?... I let you guess how your lan0 is configured...
So stop playing around trying to get mozilla display, and solve the mess you put yourself in.
Lesson one:
Boot in single user (NO GUI then, yes its tough...) then get your box to get in init 2
in that state you have no internet advanced stuff (no NFS etc...) no X1 running, but you have lan0 or lan1 configured..
Now you are on tes terminal, try to ping your gateway, does it reply?
can you ping yourself?
Did you set correctly your netmask, do the speed of ports lan match?
try an nslookup command like nslookup unix.com what output do you get?
Lesson 2
look at the man pages how to set DHCP if that is what you want, or how to configure as post #7 suggest: 2 files /etc/resolv.conf /etc/nsswitch.conf
A mistake here and you have nslookup not working...
If all you can think of using ping and nslookup gives you satisfaction
pass to init 3
or reboot...
now in GUI try mozilla if it doesnt work come back to init 2, go and look at /sbin/rc3.d and look what is launched and check all the configuration files those application use and correct the faulty then go and look at what mozilla launches, I remember it fires a shell that read also files, look what is in the script and comment out what you suspect faulty...
Even if it years since my last install of HP-UX I have more than 20 years experience with and can assure you that a bad start you pay all the life of the box... and a well installed at a begining box will never fail till you replace it I stopped last year a 10.20 I installed in 1998 and a 11.11 I installed in 2001 but had boxes installed by others like you wanting such soft to run or did not pay attention to some netwrk issues that always had something not working right at a moment like swinstall or Ignite or the mirroring etc...