ppp installing unwanted route

[Mike Tancsa]

This seems like a bit of deja vu, but I cant seem to recall if the
problem went away in the past or I worked around it.

I am trying to manage failover via an ethernet connection, and a PPPoE
connection as a backup route. Dynamic routing happens via quagga / BGP.
The problem is, ppp seems to inject a default route, even when its not
configured to.  My ppp stanza looks like


pppoe:
 add 192.168.153.2 HISADDR	
 set device PPPoE:igb2
 set server /var/run/vdsl-internet "" 0177
 set speed sync
 enable echo
 disable vjcomp
 set cd 15
 set dial
 set login
 set timeout 0
 set lqrperiod 10
 set authname spare2 at domain
 set authkey the password
 set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.0 255.255.255.0


there are no ppp.link[up|down] files.

If I start the box without ppp running, the routing table according to
quagga looks as expected


> sh ip route
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, P - PIM, A - Babel,
       > - selected route, * - FIB route

B>* 0.0.0.0/0 [20/0] via 10.255.255.1, igb0, 00:00:46

the default route is picked up from its configured peer via bgp via the
ethernet connection learned over bgp.


> sh ip bgp
BGP table version is 0, local router ID is 192.168.254.12
Status codes: s suppressed, d damped, h history, * valid, > best, =
multipath,
              i internal, r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 0.0.0.0          10.255.255.1                         102 65060 i
*> 172.30.84.0/24   0.0.0.0                  0          32768 i

Displayed  2 out of 2 total prefixes


The shell confirms as well

# netstat -nr | grep def
default            10.255.255.1       UG1          85   1500       igb0
#

Then I start up ppp

# ppp -ddial pppoe
Working in ddial mode
Using interface: tun0

and the default route is gone

but quagga sees some kernel route across tun0, but its not really there.

> sh ip route
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, P - PIM, A - Babel,
       > - selected route, * - FIB route

K>* 0.0.0.0/0 via 67.43.128.14, tun0
B   0.0.0.0/0 [20/0] via 10.255.255.1, igb0, 00:04:49

if I kill off ppp, the default route gets re-added, and I see that old
kernel route as an inactive stale entry

> sh ip route
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, P - PIM, A - Babel,
       > - selected route, * - FIB route

K   0.0.0.0/0 via 67.43.128.14 inactive
B>* 0.0.0.0/0 [20/0] via 10.255.255.1, igb0, 00:07:02


Any ideas whats going on ?

	---Mike



-- 
-------------------
Mike Tancsa, tel +1 519 651 3400
Sentex Communications, mike at sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada   http://www.tancsa.com/