01-06-2006 05:45 AM - edited 03-03-2019 11:23 AM
I have a customer who is about to come online using 2 T1s in multilink. He sent me his configuration to look over. I am not sure why he is setting up multilink in this manner. Here is the relevant config:
interface Loopback0
ip address 192.168.1.42 255.255.255.252
!
interface Serial0/0
no ip address
encapsulation ppp
pulse-time 1
ppp multilink
!
interface Serial 0/1
no ip address
encapsulation ppp
pulse-time 1
ppp multilink
!
interface Virtual-Template1
ip unnumbered Loopback0
ppp multilink
!
ip route 0.0.0.0 0.0.0.0 192.168.1.41
Typically I see multilink setup as:
interface Multilink1
ip address 192.168.1.42 255.255.255.252
ppp multilink
ppp multilink links maximum 2
ppp multilink links minimum 1
ppp multilink group 1
!
interface Serial0/0
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
!
interface Serial0/1
no ip address
encapsulation ppp
ppp multilink
ppp multilink group 1
!
ip route 0.0.0.0 0.0.0.0 192.168.1.41
I was wondering which was the better multilink setup? Is my customer on to something I am not aware of or way off base?
Thanks,
Josh
01-06-2006 06:53 AM
Hi
AFAIK we deploy configs related to virtual templates when dial in from the remote locations.
Virtual templates are logical interfaces similar to multilink interface but it can be applied dynamically based on the requirement.
As a general practice for bundling 2 T1s its multilink interface the best option being followed at present..
I would prefer u to suggest the pros/cons involved and the best operational excercise which can be availed with general multilink interface bundling..
regds
01-08-2006 03:12 PM
Thanks for everyone's reply. I have made my recommendations to my customer regarding the multilink setup. I had another customer sometime back who setup multilink with virtual-template but it seemed to cause them problems trying to bring the logical interface up. Hopefully they will just go with the more conventional setup, but it's their choice now.
Thanks,
Josh
01-07-2006 09:29 AM
Hi Josh
The config that your client has provided seems to be missing the command "multilink virtual-template"
Apart from that everything looks ok to me..
I too reckon that your method makes more sense in this scenario as we do not actually require a v-template as the dialled end is not an access server.
In your method, the multilink logical interface serves as the bundle master where as in your client's method, the virtual-access interface will be doing the job.
Hence, in your method, the NCP and hence the other characteristics of the connection will be negotiated by the multilink interface..similar to the above.
So I cannot think of any pros and cons.
Ideas, thoughts anyone ?
cheers
Arav
01-08-2006 09:28 PM
Josh,
I have two point-to-point T1 circuits bundled to a Multilink interface just as you have described above in your "typcial setup" configuration. It works great in our environment; the only catch was I needed to supply the clocking on one end since the carrier doesn't provide clocking in a point-to-point environment.
-m2
01-09-2006 02:26 AM
hi,
here i give the working config from cisco site. which uses the virtual templete.
hostname RouterA
!
!
username RouterB password your_password
ip subnet-zero
multilink virtual-template 1
!
interface Virtual-Template1
ip unnumbered Ethernet0
ppp authentication chap
ppp multilink
!
interface Serial0
no ip address
encapsulation ppp
no fair-queue
ppp multilink
pulse-time 3
!
interface Serial1
no ip address
encapsulation ppp
no fair-queue
ppp multilink
pulse-time 3
!
interface Serial2
no ip address
encapsulation ppp
no fair-queue
ppp multilink
pulse-time 3
!
interface Serial3
no ip address
encapsulation ppp
no fair-queue
ppp multilink
pulse-time 3
!
interface Ethernet0
ip address 10.17.1.254 255.255.255.0
!
router rip
network 10.0.0.0
!
end
Router B Configuration
hostname RouterB
!
!
username RouterB password your_password
ip subnet-zero
multilink virtual-template 1
!
interface Virtual-Template1
ip unnumbered Ethernet0
ppp authentication chap
ppp multilink
!
interface Serial0
no ip address
encapsulation ppp
no fair-queue
ppp multilink
pulse-time 3
!
interface Serial1
no ip address
encapsulation ppp
no fair-queue
ppp multilink
pulse-time 3
!
interface Serial2
no ip address
encapsulation ppp
no fair-queue
ppp multilink
pulse-time 3
!
interface Serial3
no ip address
encapsulation ppp
no fair-queue
ppp multilink
pulse-time 3
!
interface Ethernet0
ip address 10.17.2.254 255.255.255.0
!
router rip
network 10.0.0.0
!
end
01-09-2006 02:27 AM
Hi Matt,
Just curious to know what you meant when you said 'since the carrier doesn't provide clocking in a point-to-point environment.'
Clocking is indispensable in any serial communication setup and it is provided by the DCE (Serv Provider) equipment.
I'm inclined to think that it was an one off instance with your provider alone and it has got nothing to do with this kind of a config/setup.
Let us know what you think.
cheers
Arav
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