Device C
Configuration
router isis
net 49.0001.0000.0000.000c.00
interface ethernet2/0
ip router isis
ip address 172.21.1.2 255.255.255.0
interface serial5/0
ip router isis
ip address 172.22.1.1 255.255.255.0
The
show
isis
topology command displays the following
information about how the devices are connected within the IS-IS network:
DeviceB# show isis topology
IS-IS paths to level-1 routers
System Id Metric Next-Hop Interface SNPA
DeviceA 10 DeviceA Se2/0 *HDLC*
DeviceB --
DeviceC 10 DeviceC Se5/0 *HDLC*
IS-IS paths to level-2 routers
System Id Metric Next-Hop Interface SNPA
DeviceA 10 DeviceA Se2/0 *HDLC*
DeviceB --
DeviceC 10 DeviceC Se5/0 *HDLC*
The
show
isis
database command displays following information
for the Level 1 and Level 2 LSPs for each device in the IS-IS network.
DeviceB# show isis database
IS-IS Level-1 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
DeviceA.00-00 0x00000005 0x1A1D 1063 0/0/0
DeviceB.00-00 * 0x00000006 0xD15B 1118 0/0/0
DeviceC.00-00 0x00000004 0x3196 1133 1/0/0
IS-IS Level-2 Link State Database:
LSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
DeviceA.00-00 0x00000008 0x0BF4 1136 0/0/0
DeviceB.00-00 * 0x00000008 0x1701 1137 0/0/0
DeviceC.00-00 0x00000004 0x3624 1133 0/0/0
The
show
ip
route command displays information about the
interfaces of each device, including their IP addresses and how they are
connected to Device B:
DeviceB# show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
172.17.0.0/24 is subnetted, 1 subnets
C 172.17.1.0 is directly connected, Ethernet0/0
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, Serial4/0
172.21.0.0/24 is subnetted, 1 subnets
C 172.21.1.0 is directly connected, Serial5/0
172.22.0.0/24 is subnetted, 1 subnets
i L1 172.22.1.0 [115/20] via 172.21.1.2, Serial5/0
10.0.0.0/24 is subnetted, 1 subnets
i L1 10.1.1.0 [115/20] via 192.168.1.2, Serial2/0
C 192.168.1.0/24 is directly connected, Serial2/0
C 192.168.3.0/24 is directly connected, Serial3/0
The
show
isis
spf-log command displays logs of Level 1 and Level
2 LSPs including time of occurrence, duration, count, and the event that
triggered the LSP.
DeviceC## show isis spf-log
level 1 SPF log
When Duration Nodes Count First trigger LSP Triggers
00:01:30 0 3 7 DeviceB.00-00 PERIODIC NEWADJ NEWLSP TLVT
level 2 SPF log
When Duration Nodes Count First trigger LSP Triggers
00:01:31 0 3 7 DeviceB.00-00 PERIODIC NEWADJ NEWLSP TLVT
The figure below
illustrates the sample configuration.
Figure 1. IS-IS Routing