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(difficult) pppd and route table

 
 
KZ
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      10-04-2004, 07:12 AM
Hi,

I've got 2 computers (the first one is configured now and I'm trying to
configure the second one)
The problem is that pppd make incorrect entry in route table, I don't know
why.
This 2 computers will NOT run simultaneously. I want to swap the 1st one
with the 2nd one.


1st computer, BEFORE running pppd (the table is listed very fast):
Code:

Destination Gateway Genmask Flags Metric Ref Use
Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0

1st computer, AFTER running pppd (the table is listed very fast):
Code:

Destination Gateway Genmask Flags Metric Ref Use
Iface
213.25.2.57 0.0.0.0 255.255.255.255 UH 0 0 0
ppp0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
192.168.60.0 0.0.0.0 255.255.255.0 U 0 0 0
eth1
0.0.0.0 213.25.2.57 0.0.0.0 UG 0 0 0
ppp0

all is OK, works fine
------------------------------------------------------------------------------

2nd computer, BEFORE running pppd (the table is listed very fast):
Code:

Destination Gateway Genmask Flags Metric Ref Use
Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0

2nd computer, AFTER running pppd (the table is listed very SLOW):
Code:

Destination Gateway Genmask Flags Metric Ref Use
Iface
213.25.2.57 * 255.255.255.255 UH 0 0 0
ppp0
192.168.0.0 * 255.255.255.0 U 0 0 0
eth0
192.168.60.0 * 255.255.255.0 U 0 0 0
eth1
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0
eth0

why it did such an entry (the last one) ? instead of the correct one using
ppp0 ?

It may be important that, when I type ONCE only: (deleting default first)

route add default gw [ip_ppp0]

and than i stop pppd and start It again (the table is listed very fast):
Code:

Destination Gateway Genmask Flags Metric Ref Use
Iface
213.25.2.57 0.0.0.0 255.255.255.255 UH 0 0 0
ppp0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
192.168.60.0 0.0.0.0 255.255.255.0 U 0 0 0
eth1
0.0.0.0 213.25.2.57 0.0.0.0 UG 0 0 0
ppp0

so ... pppd add the default route correctly

when I reboot comp again ... start pppd, the default route is added
incorrectly again like this:
Code:

Destination Gateway Genmask Flags Metric Ref Use
Iface
213.25.2.57 * 255.255.255.255 UH 0 0 0
ppp0
192.168.0.0 * 255.255.255.0 U 0 0 0
eth0
192.168.60.0 * 255.255.255.0 U 0 0 0
eth1
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0
eth0

------------------------------------------------------------------------------

the pppd configuration file is the same on both machines
I use defaultroute option of course

the kernel version is the same on both machines but compilation
configuration is different

may have something to do the ARP table ??

thank you for any help,
K.Z. dipol0
 
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Moe Trin
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      10-04-2004, 08:09 PM
In article <(E-Mail Removed)>, KZ wrote:
>The problem is that pppd make incorrect entry in route table, I don't know
>why.


Most unlikely. You have something else wrong with your network setup.

>1st computer, BEFORE running pppd (the table is listed very fast):
>Code:
>
> Destination Gateway Genmask Flags Metric Ref Use

Iface
> 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0

eth0

Where is the loopback? There should also be a line for interface 'lo'.

>1st computer, AFTER running pppd (the table is listed very fast):
>Code:


Yes - but you are still missing the loopback interface. Or did you
edit that out?

>2nd computer, BEFORE running pppd (the table is listed very fast):
>Code:


As above.

>2nd computer, AFTER running pppd (the table is listed very SLOW):
>Code:
>
> Destination Gateway Genmask Flags Metric Ref Use

Iface
> 213.25.2.57 * 255.255.255.255 UH 0 0 0

ppp0
> 192.168.0.0 * 255.255.255.0 U 0 0 0

eth0
> 192.168.60.0 * 255.255.255.0 U 0 0 0

eth1
> 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0

eth0

Two things have changed. First, there is now an 'eth1' interface. Why?
pppd has nothing to do with that. Second, pppd does not add routes to
interfaces other than ppp0 unless you have made it do so - perhaps a
script in /etc/ppp/ip-up. But this is highly unlikely because when you
kill the default, it doesn't get added back by pppd. As for the 'very
fast' verses 'very slow' - this is because the command you use is trying
to look up the IP address, but can not reach the name servers. Instead
of 'route' use 'route -n'.

>why it did such an entry (the last one) ? instead of the correct one using
>ppp0 ?


It did not do so. What ever brought up eth1 added the default route. Search
through the /etc/ directory and below, to find where this error is commanded.

>It may be important that, when I type ONCE only: (deleting default first)
>
>route add default gw [ip_ppp0]
>
>and than i stop pppd and start It again (the table is listed very fast):


No, this is normal. pppd will not _replace_ an existing default route.

>so ... pppd add the default route correctly
>
>when I reboot comp again ... start pppd, the default route is added
>incorrectly again like this:


No, when your computer reboots, it is bringing up this bogus default
route - either at boot time, or when the eth1 interface is added. Find
where that is being done, and correct it.

>the pppd configuration file is the same on both machines
>I use defaultroute option of course


Yes, the problem is not pppd. The problem is the ethernet setup.

>may have something to do the ARP table ??


No - something with the configuration of the ethernet interfaces. Find
where that is done, and you will find your problem.

Old guy

 
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KZ
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      10-05-2004, 10:15 AM
On Mon, 04 Oct 2004 15:09:04 -0500, Moe Trin wrote:

>> Destination Gateway Genmask Flags Metric Ref Use

> Iface
>> 213.25.2.57 * 255.255.255.255 UH 0 0 0

> ppp0
>> 192.168.0.0 * 255.255.255.0 U 0 0 0

> eth0
>> 192.168.60.0 * 255.255.255.0 U 0 0 0

> eth1
>> 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0

> eth0
>
> Two things have changed. First, there is now an 'eth1' interface. Why?


I use eagle-usb drivers and pppoe to connect to my ISP, pppoe bring up the
virtual eth1 interface, it is needed.

> Second, pppd does not add routes to > interfaces other than ppp0 unless
> you have made it do so - perhaps a > script in /etc/ppp/ip-up.


I haven't made it do so, I just started pppd with identical options as in
the first case. The /etc/ppp/ip-up are also identical in both cases. If
pppd doesn't add the last route than what ? It is added after I run pppd.
Is it possible that pppoe added this route ?


Thanks for previous post.
Krzysztof Zygmunt
 
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KZ
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      10-05-2004, 11:10 AM
On Mon, 4 Oct 2004 09:12:40 +0200, KZ wrote:

Problem is solved. It was network configuration problem indeed. Thanks Moe
Trin.

I had to add:
192.168.0.1 gate
in my /etc/hosts file

I still don't know why pppd add correct route through ppp0 though. But it
does which is very nice
 
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