Topology:
This task includes routers R1, R2 (IOS )and R3 (IOS-XR).
Initial configuration include loopback0 interface on each router, and links between the routers.
Requirements:
1. Configure ISIS as routing protocol to provide connectivity between the routers.
2. Use area number 49.0001.
3. System-ID should be 0000.0000.000X, where X is the router number.
4. All devices should use only ISIS Level-2 routing.
5. R3 should be the DIS on the segment R1-R3.
6. R2 should be the DIS on the segment R2-R3.
7. There should be no CSNP flooding on segment R1-R2.
Solution:
Highlight the text below to reveal the solution.
This is basic ISIS single level configuration.
Segments R1-R3 and R2-R3 should be configured as multiaccess segments, on which DIS is elected.
Configure the priority to affect the DIS election process.
Segment R1-R2 should be configured point-to-point. CSPN are only flooded by DIS on multiaccess segment.
R1:
!
interface Ethernet0/0
ip address 11.0.13.1 255.255.255.0
ip router isis CCIE
isis circuit-type level-2-only
!
interface Ethernet0/1
ip address 11.0.12.1 255.255.255.0
ip router isis CCIE
isis circuit-type level-2-only
isis network point-to-point
!
interface Loopback0
ip address 11.0.1.1 255.255.255.255
ip router isis CCIE
isis circuit-type level-2-only
!
router isis CCIE
net 49.0001.0000.0000.0001.00
!
R2:
!
interface Ethernet0/0
ip address 11.0.23.2 255.255.255.0
ip router isis CCIE
isis circuit-type level-2-only
isis priority 127
!
interface Ethernet0/1
ip address 11.0.12.2 255.255.255.0
ip router isis CCIE
isis circuit-type level-2-only
isis network point-to-point
!
interface Loopback0
ip address 11.0.2.2 255.255.255.255
ip router isis CCIE
isis circuit-type level-2-only
!
router isis CCIE
net 49.0001.0000.0000.0002.00
!
R3:
!
router isis CCIE
net 49.0001.0000.0000.0003.00
interface Loopback0
address-family ipv4 unicast
!
!
interface GigabitEthernet0/0/0/0
circuit-type level-2-only
priority 127
address-family ipv4 unicast
!
!
interface GigabitEthernet0/0/0/1
circuit-type level-2-only
address-family ipv4 unicast
!
!
!
Verification:
R1#show isis neighbors
Tag CCIE:
System Id Type Interface IP Address State Holdtime Circuit Id
R2 L2 Et0/1 11.0.12.2 UP 22 00
R3 L2 Et0/0 11.0.13.3 UP 8 R3.03
R1#sh ip route isis
Codes: L - local, 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, H - NHRP, l - LISP
+ - replicated route, % - next hop override
Gateway of last resort is not set
11.0.0.0/8 is variably subnetted, 8 subnets, 2 masks
i L2 11.0.2.2/32 [115/20] via 11.0.12.2, 00:11:11, Ethernet0/1
i L2 11.0.3.3/32 [115/20] via 11.0.13.3, 00:09:27, Ethernet0/0
i L2 11.0.23.0/24 [115/20] via 11.0.13.3, 00:09:27, Ethernet0/0
[115/20] via 11.0.12.2, 00:09:27, Ethernet0/1
R2# show isis neighbors
Tag CCIE:
System Id Type Interface IP Address State Holdtime Circuit Id
R1 L2 Et0/1 11.0.12.1 UP 27 00
R3 L2 Et0/0 11.0.23.3 UP 26 R2.01
RP/0/0/CPU0:R3#show isis neighbors
Sun Dec 13 18:41:31.243 UTC
IS-IS CCIE neighbors:
System Id Interface SNPA State Holdtime Type IETF-NSF
R1 Gi0/0/0/0 aabb.cc00.0400 Up 23 L2 Capable
R2 Gi0/0/0/1 aabb.cc00.0100 Up 7 L2 Capable
