Dynamic hostname
This example shows how to configure Dynamic Hostname for an ISIS instance. Dynamic hostname is the method of mapping name-to-systemID. It allows the routing protocol to advertise symbolic names in the IS-IS PDUs. This is done by the addition of a new TLV which allows the IS-IS routers to include the name-to-systemID mapping data in their LSPs. This allows for simple and reliable transport of name mapping across IS-IS networks. Dynamic hostname can be either the hostname of the node or the tag of the configured ISIS instance.
Note: Dynamic-hostname has to be configured on all nodes for it to take effect.
Topology
Figure 6-42: Basic dynamic hostname topology
Configuration
R1
(config)#interface eth1 | Enter interface mode. |
(config-if)#ip router isis ABC | Enable IS-IS routing on an interface for area 49 (ABC). |
(config)#ip address 21.21.21.2/24 | Configure IP address on interface. |
(config-if)#exit | Exit interface mode. |
(config)#router isis ABC | Create an IS-IS routing instance for area 49 (ABC). |
(config-router)#is-type level-2-only | Configure instance as level-2-only routing. |
(config-router)#net 49.0000.0000.0001.00 | Set a Network Entity Title for this instance, specifying the area address and the system ID. |
(config-router)#dynamic-hostname | Configure the hostname to be advertised for an ISIS instance. |
R2
(config)#interface eth1 | Enter interface mode. |
(config)#ip address 21.21.21.1/24 | Configure IP address on interface. |
(config-if)#ip router isis ABC | Enable IS-IS routing on an interface for area 49 (ABC). |
(config-if)#exit | Exit interface mode. |
(config)#router isis ABC | Create an IS-IS routing instance for area 49 (ABC). |
(config-router)#is-type level-2-only | Configure instance as level-2-only routing. |
(config-router)#net 49.0000.0000.0002.00 | Set a Network Entity Title for this instance, specifying the area address and the system ID. |
(config-router)#dynamic-hostname | Configure the hostname to be advertised for an ISIS instance. |
Validation
R1#show clns neighbors
Total number of L1 adjacencies: 0
Total number of L2 adjacencies: 1
Total number of adjacencies: 1
Tag ABC: VRF : default
System Id Interface SNPA State Holdtime Type Protocol
R2 eth1 5254.002a.230a Up 28 L2 IS-IS
R2#show clns neighbors
Total number of L1 adjacencies: 0
Total number of L2 adjacencies: 1
Total number of adjacencies: 1
Tag ABC: VRF : default
System Id Interface SNPA State Holdtime Type Protocol
R1 eth1 5254.00dc.0b76 Up 7 L2 IS-IS
R1#show clns is-neighbors
Tag ABC: VRF : default
System Id Interface State Type Priority Circuit Id
R2 eth1 Up L2 64 0000.0000.0001.01
R2#show clns is-neighbors
Tag ABC: VRF : default
System Id Interface State Type Priority Circuit Id
R1 eth1 Up L2 64 0000.0000.0001.01
R1#show isis topology
Tag ABC: VRF : default
IS-IS paths to level-2 routers
System Id Metric Next-Hop Interface SNPA
R1 --
R2 10 R2 eth1 5254.002a.230a
R2#show isis topology
Tag ABC: VRF : default
IS-IS paths to level-2 routers
System Id Metric Next-Hop Interface SNPA
R1 10 R1 eth1 5254.00dc.0b76
R2 --
R1#show isis database
Tag ABC: VRF : default
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R1.00-00 * 0x0000000B 0x1D6B 1170 0/0/0
R1.01-00 * 0x00000004 0x1BBC 538 0/0/0
R2.00-00 0x0000000C 0x0D79 1166 0/0/0
R2#show isis database
Tag ABC: VRF : default
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
R1.00-00 0x0000000B 0x1D6B 1078 0/0/0
R1.01-00 0x00000004 0x1BBC 445 0/0/0
R2.00-00 * 0x0000000C 0x0D79 1075 0/0/0
Last modified date: 07-13-2023