PPP Host Route Injection Delay

From: Colm O'Leary (co.oleary@gmail.com) ((co.oleary@gmail.com))
Date: Thu Mar 27 2008 - 14:15:18 ART


Hi Group,
   I am having a design problem that I am hoping someone has stumbled across
in a previous life. I have two headend routers configured as access servers
for branch sites. The branch sites have a ADSL into MPLS as their primary
path and isdn bra as their secondary path. The secondary path is only ever
used if the primary is unavailable for all traffic.
   At the headend my telco is load balancing the isdn call in a 50:50 ratio
across both headend routers. The routing at the headend uses a static route
for the remote LAN which points to the ip address of the dialer interface of
the branch router. A problem arises when the branch site dials in in a
failover scenario. The first packet sent from the branch hits the back
office server which immediately replies, when the packet arrives back to the
the headend router, the router is unable to route the packet because the
route to its destination is referencing the remote branch dialers ip address
which does not appear in the routing table as a directly connected network.
For the second a thirds packets all works ok as the ppp host route is now in
the routing table.
   An application running at the branch has brought around this requirement.
The application session times out if the first packet sent is not
acknowledged. The application is udp based. Is there any way that I can
speed up the injection of the host route into the routing table?

Thanks

Colm
CCIE#17471

            [SERVER]
_______________________________
[HEADEND 1] [HEADEND 2]
          . .
           . .
            . .
            [ISDN]
               .
               .
               .
               .
           [BRANCH]

*BRANCH CONFIG*

!
ip cef
!

isdn switch-type basic-net3
!
interface BRI0
 no ip address
 encapsulation ppp
 no ip mroute-cache
 shutdown
 dialer pool-member 1
 isdn switch-type basic-net3
 isdn point-to-point-setup
 isdn static-tei 0
 no cdp enable
 ppp authentication chap
!
interface Vlan501
 description L3 Connection to Integrated 8 Port Switch
 ip address 10.80.0.1 255.255.255.0
 ip access-group 100 in
 no autostate
!
interface Dialer1
 bandwidth 64
 ip address 10.84.0.1 255.255.255.254
 encapsulation ppp
 no ip mroute-cache
 dialer pool 1
 dialer string removed
 dialer hold-queue 100
 dialer-group 1
 no cdp enable
 ppp authentication chap
 ppp chap hostname removed
 ppp chap password removed
!

!
ip route 0.0.0.0 0.0.0.0 Dialer1 250
!
!

dialer-list 1 protocol ip list 100

*HEADEND CONFIG*

controller E1 7/0
 framing NO-CRC4
 pri-group timeslots 1-31
!
interface Serial7/0:15
 no ip address
 encapsulation ppp
 ip mroute-cache
 dialer rotary-group 2
 dialer-group 2
 isdn switch-type primary-net5
 isdn incoming-voice modem
 no fair-queue
 no cdp enable
!
interface Dialer2
 ip address 10.110.2.1 255.255.255.0
 encapsulation ppp
 dialer in-band
 dialer idle-timeout 4
 dialer fast-idle 5
 dialer-group 2
 no peer default ip address
 no fair-queue
 no cdp enable
 ppp authentication pap chap callin radius-auth-ppp
!
interface BVI1
 ip address 10.67.35.1 255.255.255.0
!
ip route 10.80.0.0 255.255.255.0 10.84.0.1
!
dialer-list 2 protocol ip permit



This archive was generated by hypermail 2.1.4 : Tue Apr 01 2008 - 07:53:54 ART