Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements
Webcast-Catalyst9k
New Member

ISIS encapsulation fails

I tried to merge rip to isis.

I have configured isis correctly and enable it on serial1/0(encapsulation ppp)

but the debug isis adj display the error msg such as:

encapsulation failure on serial1/0 IIH

But the interface is ok when running rip and is now working .

What's the reason for this error log? (If I enable isis on

peer router of serial 1/0 ,the isis nbr must not establish.)

Thanks for any clue.

10 REPLIES
Gold

Re: ISIS encapsulation fails

How did you enable IS-IS on the interface? Is this a multipoint or point-to-point interface? Could you post the config for the interface and IS-IS here?

Russ.W

Bronze

Re: ISIS encapsulation fails

IS-IS runs over CLNS. Enabling IS-IS on your interface may not establish a PPP CLNS NCP connection automatically. You might try shutting and un-shutting one of your serial interfaces to see if this initiates a CLNS NCP.

Good luck!

Mark

New Member

Re: ISIS encapsulation fails

I can remember back main configuration about isis as follow:

routing clns

!

int fa0/0

ip router isis backbone

clns router isis backbone

!

int s1/0

ip router isis branch1

isis circuit-type level-1

no isis hello-padding

!

router isis backbone

net 49.0001.0100.1001.0001

is-type level-2

metric-styl wide trans

ignore-lsp-error

!

router isis branch1

net 49.0002.0100.1001.0001

metric-style wide

ignore-lsp-error

!

I have assign all serial interfaces into branch1 area and Fa0/0 to backbone area.(the spf-log display that LAN IIH send

correctly but all serial's PPP IIH encapsulation fails)

Althrough forbiden,I have shut down one of serial int and recovery it again,but it seems not works!)

I have doubt the function of ppp NCP but it seems ppp support

CLNS )

The serial ints are all working in gear.

I can not get the reason about .

Gold

Re: ISIS encapsulation fails

First, why are you running two IS-IS processes? If yout're just trying to route IP using IS-IS, you should probably only have one IS-IS process. You don't use IS-IS processes like OSPF areas.

Second, is int s1/0 up and running? What does show ip int brief show about this interface?

Russ.W

New Member

Re: ISIS encapsulation fails

I am ready to make defferent interfaces on the core router belong to multi L1 isis area clearly.( Seperated L1 LSP database seems easyly to troubleshoot )

So I have chosen multi isis process.

Yes, int s1/0 is up and working (business traffic is flowing

normally,I must merge rip to isis without flag day. the s1/0 interface is line up and protocol up without ACL to filter

CLNP pkts. for ensure I have test MTU packets from 100 -1500 to through this serial int sucessfully.

Yesterday , I test isis on a idle serial int of this router at back-to-back enviroment and serial IIH is sent normally with 1499 mtu. I cannot find a way out. It isn't seems a hardware or software problem.

Thanks for hint .

Bronze

Re: ISIS encapsulation fails

When you do a "show interface" for your serial line, it will show you the status of IPCP. Do you see an equivalent status for CLNS CP? I don't know what it would be called, perhaps CLNSCP. This could indicate whether or not the interface is CLNS-aware.

Mark

Gold

Re: ISIS encapsulation fails

How do you intend to get the routes from the L1 area to the L2 area? It's much much easier to use IS-IS the way it was designed, with L1 and L2 routes in the same database.... :-) I think it's likely that you are having issues with building the L2 only adjacency over this interface--it is the L2 only interface, isn't it?

Russ.W

New Member

Re: ISIS encapsulation fails

I remember the show interface s1/0 display the IPCP open but

I haven't mind some line about clns NCP,if exist maybe I should see it....see it tomorrow.

And I have debug ppp err today :

deb ppp error

Sep 15 08:11:26: Se1/0 PPP: Outbound clns_is packet dropped, OSICP state is Listen

Sep 15 08:11:35: Se1/0 PPP: Outbound clns_espacket dropped,

OSICP state is Listen

It seems ppp NCP problem.....

And today I have tried to use HDLC encap on serial1/0 then

serial IIH successfully sent with mtu 1499.

PS:

I want to use redistribute isis ip level2-into-level1 cmd to get routes back to L1(of course I will summary them first)

The s1/0 is config to run L1 only for branch1, and L2 is running on the Fa0/0 and successful establish L2 nbr relation.

I want to use multi isis process to seperate multi area's L1

routes(maybe ospf habit....:)Is it source wasted or misfit?

Sometimes I feel isis database is hard to rebuild if I clear

isis database .

Gold

Re: ISIS encapsulation fails

I'll leave the ppp issues to someone more familiar with ppp. :-)

The redistribute ip level2-into-level1 won't do what you want to do in this case--it only "leaks" routes from level 2 into level 2 in the same process, not between two processes. An L2 only area won't work at all, you have to run L1 and L2 anyway in the backbone, so it's just as well to use a single process, running both L1 and L2. Rebuilding the database when it clears shouldn't be any harder either way. The router still has to do the work of building all the databases, etc.

If you really want to do this, you have to do redistribution from the routing table, just like between EIGRP and IS-IS, or OSPF and IS-IS, etc. The two processes won't talk at all except through the routing table.

One process is going to be easier to configure and maintain in the long run. :-)

Russ.W

New Member

Re: ISIS encapsulation fails

Thanks for your help and indicate my mistake about isis. I adjust the configurations to one process.(if encap do works I will deploy them)

Today and tomorrow I have to participate in power supply design and no choice to attach routers...Sometimes I feel very envy about ones who can touch routes every day and want to become someone versed in routing like u :)

221
Views
0
Helpful
10
Replies
CreatePlease to create content