# can't access university domain over pppoe from home [solved]

## sfabius

I have a laptop that I use at work (University of Pittsburgh) and at home. At work, it connnects ethernet eth0 with a fixed IP address.

At home, I recently got DSL (yay), and am connected using pppoe. I can ping and access anything outside the university domain, but nothing inside the domain (or in the IP address domain -- 136.142.XXX.XXX). I've tried setting iface_eth0="up" in /etc/conf.d/net, but the IP address comes back even after I bring up eth0. My wife's windows laptop connects to these websites without any trouble.

I'm using Firestarter to run a firewall but I verything open going out.

So i think there's something where the university won't accept connections from a 136.142 IP address when it clearly comes from outside the university (the university tech people can't seem to even figure out my problem -- they keep telling me to call my DSL provider). But I don't know how to fix this. I'd like to get it so I can have one setup for home and one for work. I have different login scripts for whether I am at work or at home. Can somebody help me figure out what to do next?

(I've done some searching here, but it was hard to know what to search for; apologies and thanks if you can find me a topic on this.)Last edited by sfabius on Fri May 27, 2005 11:12 pm; edited 1 time in total

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## NeddySeagoon

sfabius,

Can you traceroute to a Uni IP you know works, to see where your packets are being dropped?

```
emerge traceroute
```

if needed.

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## sfabius

Here (this is to the IP I usually use as my gateway -- 136.142.130.1):

```
traceroute to hsrp-vlan130-130.gw.pitt.edu (136.142.130.1), 30 hops max, 40 byte packets

 1  spare5.linguist.pitt.edu (136.142.130.89)  2999.797 ms !H  3000.260 ms !H  3000.720 ms !H

```

"spare5" is the name of my machine

[is it safe to put my IP address up here or should I X part of it out?]

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## sfabius

BTW, I tried changing my eth0 to ifconfig_eth0="up". When I did /etc/init.d/net.eth0, I get:

```
 * Keeping kernel configuration for eth0
```

What's that?

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## NeddySeagoon

sfabius,

That traceroute would be OK if you were on the Uni but from home it should be more like this from home.

I'm in the UK, so you will have less 'hops' 

```
$ /usr/sbin/traceroute 136.142.130.1

traceroute to hsrp-vlan130-130.gw.pitt.edu (136.142.130.1), 30 hops max, 38 byte packets

 1  Moriarty (192.168.100.1)  0.421 ms  0.196 ms  0.188 ms

 2  adsl (62.3.120.142)  1.171 ms  1.714 ms  1.050 ms

 3  gadamer-dsl.zen.net.uk (62.3.83.3)  21.751 ms  21.161 ms  21.890 ms

 4  bolzano-ge-0-0-1-1.wh.zen.net.uk (62.3.80.225)  22.086 ms  21.113 ms  22.007 ms

 5  195.16.169.89 (195.16.169.89)  20.060 ms  20.929 ms  19.923 ms

 6  so-4-1-0.mp1.Manchesteruk1.Level3.net (4.68.113.101)  22.144 ms  20.887 ms  21.939 ms

 7  so-1-1-0.bbr1.London1.Level3.net (4.68.128.73)  28.054 ms ae-1-0.bbr2.London1.Level3.net (212.187.128.57)  29.451 ms so-1-1-0.bbr1.london1.level3.net (4.68.128.73)  28.984 ms

 8  ge-6-0.core1.London1.Level3.net (212.187.131.45)  27.181 ms ge-1-2.core1.london1.level3.net (212.187.131.165)  29.274 ms ge-6-0.core1.london1.level3.net (212.187.131.45)  29.116 ms

 9  ge-5-0-0.ar2.LON3.gblx.net (208.51.239.161)  29.698 ms  29.327 ms  27.738 ms

10  so0-0-0-2488M.ar3.jfk1.gblx.net (67.17.72.30)  96.427 ms  94.863 ms  96.044 ms

11  Pittsburgh-Supercomputing.so-2-1-1.ar3.JFK1.gblx.net (208.50.254.46)  118.203 ms  117.320 ms  117.645 ms

12  bar-ge-4-3-0-0.3rox.net (192.88.115.1)  117.765 ms  117.286 ms  117.858 ms

13  pitt-cl-i1.3rox.net (192.88.115.149)  118.092 ms  117.006 ms  117.648 ms

14  cl2-vlan712.gw.pitt.edu (136.142.2.162)  115.973 ms  116.937 ms  117.688 ms

15  cl1-cl2-pp.gw.pitt.edu (136.142.253.222)  119.999 ms * *
```

It looks like you are trying to use your Uni static IP from home and can't because your ISP does not know how to route it.

What does 

```
route -n
```

 show when you are at home?

and /etc/resolv.conf

You need two completely different set-ups

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## sfabius

Thanks -- I know I need two setups but the damn thing seems to keep the Uni setup even when I change /etc/conf.d/net. I guess I just need to kow exactly what needs to change from home. I just use adsl-setup and adsl-start.

```
# route -n

Kernel IP routing table

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

10.6.8.1        0.0.0.0         255.255.255.255 UH    0      0        0 ppp0

136.142.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth0

127.0.0.0       127.0.0.1       255.0.0.0       UG    0      0        0 lo

0.0.0.0         10.6.8.1        0.0.0.0         UG    0      0        0 ppp0

```

```
# cat /etc/resolv.conf 

nameserver 151.201.0.39

nameserver 151.201.0.38

```

And my current /etc/conf.d/net (note commented out parts that I use for the Uni; I changed it to this and then restarted net.eth0 .

```
# cat /etc/conf.d/net

# /etc/conf.d/net:

# $Header: /home/cvsroot/gentoo-src/rc-scripts/etc/conf.d/net,v 1.7 2002/11/18 19:39:22 azarah Exp $

# Global config file for net.* rc-scripts

# This is basically the ifconfig argument without the ifconfig $iface

#

#iface_eth0="136.142.130.89 broadcast 136.142.255.255 netmask 255.255.0.0"

ifconfig_eth0="dhcp"

# For setting the default gateway

#

#gateway="eth0/136.142.130.1"

```

I've also tried iface_eth0="up".

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## NeddySeagoon

sfabius,

Ah!

```
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface

10.6.8.1        0.0.0.0         255.255.255.255 UH    0      0        0 ppp0

136.142.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth0 
```

When you are at home,

you are still sending Uni bound packets to eth0, which is why they don't reach the Uni.

You need to remove that line from your routing table. From your setup, its not clear how it got there.

```
route del 136.142.0.0/16
```

is what you need. Then you should be in businnes because Uni bound packets will be sent to your defualt gateway.

Next is to automate it.

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## sfabius

OK, thanks, let's try that:

```
# route del 136.142.0.0/16

route: netmask 0000ffff doesn't make sense with host route

Usage: route [-nNvee] [-FC] [<AF>]           List kernel routing tables

       route [-v] [-FC] {add|del|flush} ...  Modify routing table for AF.

blah blah blah

```

Maybe: 

```
# route del 136.142.0.0   

SIOCDELRT: No such process

```

???

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## NeddySeagoon

sfabius,

Try 

```
route del -net 136.142.0.0
```

or 

```
route del -net 136.142.0.0/16
```

with or without eth0 on the end.

The IP address 136.142.0.0 cannot be a host route, since its a network address, so I don't understand the error.

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## sfabius

Got it, thanks! It works.

I have eth0 come up at boot, and then when I log into X I have an "Xhome" script that takes it down. Is that the problem? Should I just put the "route del" command in that script?

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## NeddySeagoon

sfabius,

Yes, that will be the problem. The route does not get deleted when you take the interface down.

Adding the

```
route del
```

is probably as good a way to fix it as any.

If you do not use eth0 at home, you may want to look at ifplug, which sets up networking 'on the fly' depending if the link on eth0 is alive (plugged in) or not.

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## sfabius

OK I'll look into ifplug. Thanks for your help!

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