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ISIS net Address configuration

Can any please let me know how to configure NET address in ISIS?

Is there any document whcih provide the conversion from IP Address to NET address details?

4 REPLIES
Hall of Fame Super Silver

Re: ISIS net Address configuration

Hello Ganpat,

the NET address is a CLNS address and it is unique for the device

(CLNS doesn't use a different L3 address on different interfaces).

There is no corrispondence with IP address(es) on the device.

In designing your IS-IS networks routers in the same area need to be configured with a net with the same area-id.

the net is formed by two parts:

area-id

system-id

system-id has to be unique in the domain.

So you choice the net on your devices.

systems with same area-id can build L1 adjancencies

systems with different area-id can become L2 neighbors.

see

http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a0080093f38.shtml

Hope to help

Giuseppe

Re: ISIS net Address configuration

I think Ganpat was asking about the trick of defining a unique SysID by padding a dotted-decimal loopback IP address with zeros. On the URL posted by Guiseppe, you can see this trick occuring in the configuration of

Router 1:

interface Loopback0

ip address 172.16.1.1 255.255.255.255

!

router isis

net 49.0001.1720.1600.1001.00

1) pad loopback with zeros (we pad each octet to 3 digits):

172.16.1.1 ---> 172.016.001.001

2) rearrange the bits to 3 groups of 4 digits:

172.016.001.001---> 1720.1600.1001

3) add area prefix (49.0001) and NSEL suffix (.00)

49.0001.1720.1600.1001.00

The same trick has been used in the configuration of Router2, but not in Router 3.

Hall of Fame Super Silver

Re: ISIS net Address configuration

Hello Mary,

yes Ganpat could be asking this.

Actually, we use something similar in our customer network but we put zeroes on the left:

example

!

interface Loopback8

ip address 10.80.34.15 255.255.255.255

ip router isis evento

!

router isis evento

net 49.1011.0080.0034.0015.00

is-type level-1

metric-style wide

log-adjacency-changes

display-route-detail

!

Hope to help

Giuseppe

Community Member

I got a NET address as like

I got a NET address as like follow

59.346e.8012.3456.0020.1001.0105

Can i find? which one is area id.

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