Subject: Re: mac eventually can't see the internet

From: Cory Riddell <[email-masked]>
Date: Fri, 21 Sep 2001 18:26:30 -0400

I have a 3-machine network.  My server/firewall is a RH7.1 machine 
(basicaly a fresh install).  It has two NICs.  eth0 goes to the 
internet and eth1 connects to my two other machines (pc and an iMac). 
 I ran lokkit, selected high security and marked eth1 as a trusted 
device.  Then:
ipchains -P forward DENY
ipchains -A forward -i eth0 -j MASQ
and ip_forward is on.

I've also setup Samba for the PC and 
netatalk-1.4b2+asun2.1.4-0.i368.rpm.  The pc works flawlessly.  The 
iMac works great for a while (internet, printing on a printer 
connected to the server, etc..)  But after 5-30 minutes, the mac is 
no longer able to see the internet.  I can still ping the mac and the 
mac can still see a shared directory on the linux box, but it cannot 
see the internet.  No http, and no email.

Any ideas?  How do I go about diagnosing a problem like this?

ifconfig tells me:
eth0 Link encap:Ethernet  HWaddr XX:XX:XX:XX:XX:XX  
     inet addr:XX.XX.XX.XX  Bcast:XX.XX.XX.255  Mask:255.255.255.0
     UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
     RX packets:121781 errors:0 dropped:0 overruns:0 frame:0
     TX packets:4935 errors:0 dropped:0 overruns:0 carrier:0
     collisions:171 
eth1 Link encap:Ethernet  HWaddr XX:XX:XX:XX:XX:XX  
     inet addr:192.168.0.1  Bcast:192.168.0.255  Mask:255.255.255.0
     EtherTalk Phase 2 addr:65280/178
     UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
     RX packets:120865 errors:0 dropped:0 overruns:0 frame:0
     TX packets:4831 errors:0 dropped:0 overruns:0 carrier:0
     collisions:666 
lo   Link encap:Local Loopback  
     inet addr:127.0.0.1  Mask:255.0.0.0
     EtherTalk Phase 2 addr:0/0
     UP LOOPBACK RUNNING  MTU:16436  Metric:1
     RX packets:6 errors:0 dropped:0 overruns:0 frame:0
     TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
     collisions:0 

Please help!
Thanks,
Cory

---

From: Cory Riddell <[email-masked]>
Date: Sun, 23 Sep 2001 20:53:22 -0400

Thanks for the reply.  I don't think it is a hardware problem because 
the mac can still see the rest of the network, just not the internet 
(no http, no email).  I've answered some of your questions below.

If you (or anybody on the list) can suggest other diagnostics, I 
would greatly appreciate the help.

On Fri, 21 Sep 2001 19:37:14 -0400, Chip Mefford wrote:
>First, to trouble shoot the network, don't do it
>all in one bite. Turn ipchains off. Does it work?
Do you mean turn ipchains off after the mac can no longer see the 
internet?  I'm afraid to run without ipchains because my machine was 
recently rooted.  That's why this is a fresh install of RH7.1  :)

>Or does it not. If so, look there, if not,
>what are all of those collisions about?
I did a little research about the collisions and it seems the biggest 
problem here is running the NICs in full duplex.  I have checked all 
of the cards on my network and all are running half duplex.  I 
downloaded Apple's duplexer extension to ensure it was running at 
half duplex.

>Are you running any printers?
Yes.  I have an ink-jet on the linux box that the mac can see and 
print to.

>What ver OS on the mac?
8.6

>What do the logs say?
Which logs?  The last part of /var/log/messages says:
Sep 23 20:00:25 porky kernel: NET4: AppleTalk 0.18a for Linux NET4.0
Sep 23 20:00:25 porky atalkd[1011]: restart (1.4b2+asun2.1.4)
Sep 23 20:00:26 porky smb: smbd startup succeeded
Sep 23 20:00:26 porky smb: nmbd startup succeeded
Sep 23 20:00:26 porky anacron: anacron startup succeeded
Sep 23 20:00:26 porky atalkd[1011]: zip_getnetinfo for eth1
Sep 23 20:00:27 porky linuxconf: Running Linuxconf hooks:  succeeded
Sep 23 20:00:35 porky atalkd[1011]: zip_getnetinfo for eth1
Sep 23 20:00:45 porky atalkd[1011]: zip_getnetinfo for eth1
Sep 23 20:00:55 porky atalkd[1011]: config for no router
Sep 23 20:00:56 porky atalkd[1011]: ready 0/0/0
Sep 23 20:00:56 porky atalk: atalkd startup succeeded
Sep 23 20:01:09 porky papd[1087]: restart (1.4b2+asun2.1.4)
Sep 23 20:01:09 porky atalk: papd startup succeeded
Sep 23 20:01:09 porky atalk: afpd startup succeeded
Sep 23 20:01:15 porky papd[1087]: register HP697C:LaserWriter@*
Sep 23 20:01:15 porky afpd[1092]: porky:AFPServer@* started on 
65280.178:130 (1.4b2+asun2.1.4)
Sep 23 20:01:15 porky afpd[1092]: ASIP started on 127.0.0.1:548(1) 
(1.4b2+asun2.1.4)
Sep 23 20:01:15 porky afpd[1092]: uam: uams_guest.so loaded
Sep 23 20:01:15 porky afpd[1092]: uam: uams_clrtxt.so loaded
Sep 23 20:01:15 porky afpd[1092]: uam: uams_dhx.so loaded
Sep 23 20:01:15 porky afpd[1092]: uam: "DHCAST128" available
Sep 23 20:01:15 porky afpd[1092]: uam: "Cleartxt Passwrd" available
Sep 23 20:01:15 porky afpd[1092]: uam: "No User Authent" available
Sep 23 20:29:54 porky gdm(pam_unix)[1066]: session opened for user 
root by (uid=0)
Sep 23 20:29:54 porky gdm[1066]: gdm_slave_session_start: root on :0
Sep 23 20:29:58 porky modprobe: modprobe: Can't locate module 
sound-slot-0
Sep 23 20:29:58 porky modprobe: modprobe: Can't locate module 
sound-service-0-0
Sep 23 20:30:03 porky gnome-name-server[1206]: starting
Sep 23 20:30:03 porky gnome-name-server[1206]: name server starting
Sep 23 20:30:04 porky kernel: hdc: ATAPI 8X CD-ROM drive, 128kB 
Cache, DMA
Sep 23 20:30:04 porky kernel: Uniform CD-ROM driver Revision: 3.12

Thanks,
cory

>On 2001.09.21 18:26 Cory Riddell wrote:

-- 
Cory Riddell, [email-masked] on 09/23/2001