Monday, 18 March 2019

EIGRP STUB and Configuration


EIGRP STUB

Stub routing is one way to limit queries. A stub router is one that is connected to on more than two neighbors and should be a transit router. 


The EIGRP stub routing feature improve network stability, reduces resource utilization, and simplifies remote router (spoke) configuration. Stub routing is commonly used in a Hub-and-Spoke topology.


Here is the command:

R1(config-router)#EIGRP STUB ?
  connected       Do advertise connected routes
  leak-map        Allow dynamic prefixes based on the leak-map
  receive-only    Set receive only neighbor
  redistributed   Do advertise redistributed routes
  static                 Do advertise static routes
  summary         Do advertise summary routes


  • Connected means the router advertise connected routes only for those interfaces which matched with a network command.
  •  Leak-map means the router advertise only which is specified by a leak-map
  •  Receive-only means the router do not advertise any routes. And this option can be used with any other option.
  • Redistribution means the router advertise only the redistributed routes.
  • Static means the router advertise only the static routes with redistributed static command configured.
  • Summary means the router advertise only auto summarized or statically configured summary routes
NOTE: By default is connected and summary.

Before we start  EIGRP configuration check out some important  of EIGRP CCIE exam topics.

Here is the lists of all EIGRP labs and theories CCNA to CCIE

1.Enhanced Interior Gateway Routing Protocol (EIGRP)

2.Stuck In Active (EIGRP)

3.EIGRP Equal-Cost and Unequal-Cost load balancing

4.Route filtering passive interface

5.Route summarization

6.EIGRP STUB and Configuration

7. Routing Protocol Authentication (EIGRP ) and configuration

let's see the configuration for a better understanding: -

Topology:


 Goal:
  • configure the topology as per the diagram.
  • configure EIGRP 650001 advertise interfaces and disable auto-summary.
  • make sure only one route advertises to router 1 and router 2 from router 3
  • after verifying the summary now configure EIGRP STUB on router 1 preventing sending any routes to router 2 make sure router 2 receives routes only from router 2.

R1#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/0        10.1.1.1        YES manual up                    up
Serial3/0                     1.1.1.1         YES manual up                    up
Loopback0              11.0.0.1        YES manual up                    up
Loopback1              11.0.1.1        YES manual up                    up
Loopback2              11.0.2.1        YES manual up                    up
Loopback3              11.0.3.1        YES manual up                    up


R2#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/0        20.1.1.1        YES manual up                    up
Serial3/0                    1.1.1.2         YES manual up                    up
Serial3/1                    2.1.1.1         YES manual up                    up
Serial3/2                    3.1.1.1         YES manual up                    up
Loopback0              12.0.0.1        YES manual up                    up
Loopback1              12.0.1.1        YES manual up                    up
Loopback2              12.0.2.1        YES manual up                    up
Loopback3              12.0.3.1        YES manual up                    up


R3#show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
FastEthernet0/0        30.1.1.1        YES manual up                    up
Serial3/1                    2.1.1.2         YES manual up                    up
Loopback0              13.0.0.1        YES manual up                    up
Loopback1              13.0.1.1        YES manual up                    up
Loopback2              13.0.2.1        YES manual up                    up
Loopback3              13.0.3.1        YES manual up                    up




R1(config)#router eigrp 65001
R1(config-router)#network 1.0.0.0
R1(config-router)#network 10.0.0.0
R1(config-router)#no auto-summary
R1(config-router)#exit


R2(config)#router eigrp 65001
R2(config-router)#network 1.0.0.0
R2(config-router)#network 1.0.0.0

*Mar 18 12:25:38.567: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 1.1.1.1 (Serial3/0) is up: new adjacency

R2(config-router)#network 2.0.0.0
R2(config-router)#network 20.0.0.0
R2(config-router)#no auto-summary
R2(config-router)#exit

R3(config)#router eigrp 65001
R3(config-router)#network 2.0.0.0

*Mar 18 12:26:16.707: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 2.1.1.1 (Serial3/1) is up: new adjacency

R3(config-router)#network 13.0.0.0
R3(config-router)#network 30.0.0.0
R3(config-router)#no auto-summary
R3(config-router)#exit

R2#show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(65001)
H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                                                  (sec)             (ms)       Cnt Num
1   2.1.1.2                 Se3/1                    12 00:08:12   73   438  0  6
0   1.1.1.1                 Se3/0                    14 00:08:50   67   402  0  6


R1#show ip route eigrp
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

D     2.0.0.0/8 [90/2681856] via 1.1.1.2, 00:10:28, Serial3/0
      13.0.0.0/24 is subnetted, 4 subnets
D        13.0.0.0 [90/2809856] via 1.1.1.2, 00:02:34, Serial3/0
D        13.0.1.0 [90/2809856] via 1.1.1.2, 00:02:34, Serial3/0
D        13.0.2.0 [90/2809856] via 1.1.1.2, 00:02:34, Serial3/0
D        13.0.3.0 [90/2809856] via 1.1.1.2, 00:02:34, Serial3/0
D     20.0.0.0/8 [90/2172416] via 1.1.1.2, 00:06:46, Serial3/0
D     30.0.0.0/8 [90/2684416] via 1.1.1.2, 00:05:52, Serial3/0


R2#show ip route eigrp
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

D     10.0.0.0/8 [90/2172416] via 1.1.1.1, 00:09:56, Serial3/0
      13.0.0.0/24 is subnetted, 4 subnets
D        13.0.0.0 [90/2297856] via 2.1.1.2, 00:01:57, Serial3/1
D        13.0.1.0 [90/2297856] via 2.1.1.2, 00:01:57, Serial3/1
D        13.0.2.0 [90/2297856] via 2.1.1.2, 00:01:57, Serial3/1
D        13.0.3.0 [90/2297856] via 2.1.1.2, 00:01:57, Serial3/1
D     30.0.0.0/8 [90/2172416] via 2.1.1.2, 00:05:15, Serial3/1



(now we are going to configure summary route)

R3(config)#interface serial 3/1
R3(config-if)#ip summary-address eigrp 65001 13.0.0.0 255.255.252.0

*Mar 18 12:39:48.235: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 2.1.1.1 (Serial3/1) is resync: summary configured


R3(config)#router eigrp 65001
R3(config-router)#eigrp stub ?
  connected      Do advertise connected routes
  leak-map       Allow dynamic prefixes based on the leak-map
  receive-only   Set receive only neighbor
  redistributed  Do advertise redistributed routes
  static         Do advertise static routes
  summary        Do advertise summary routes
  <cr>
R3(config-router)#eigrp stub summary

*Mar 18 12:42:36.931: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 2.1.1.1 (Serial3/1) is down: peer info changed

*Mar 18 12:42:37.375: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 2.1.1.1 (Serial3/1) is up: new adjacency
R3(config-router)#end

R2#show ip route eigrp
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

D     10.0.0.0/8 [90/2172416] via 1.1.1.1, 00:17:21, Serial3/0
      13.0.0.0/22 is subnetted, 1 subnets
D        13.0.0.0 [90/2297856] via 2.1.1.2, 00:00:22, Serial3/1



R1#show ip route eigrp
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


D     2.0.0.0/8 [90/2681856] via 1.1.1.2, 00:19:02, Serial3/0
      13.0.0.0/22 is subnetted, 1 subnets
D        13.0.0.0 [90/2809856] via 1.1.1.2, 00:02:07, Serial3/0
D     20.0.0.0/8 [90/2172416] via 1.1.1.2, 00:15:20, Serial3/0




R1(config)#router eigrp 65001
R1(config-router)#eigrp stub ?
  connected      Do advertise connected routes
  leak-map       Allow dynamic prefixes based on the leak-map
  receive-only   Set receive only neighbor
  redistributed  Do advertise redistributed routes
  static         Do advertise static routes
  summary        Do advertise summary routes
  <cr>


R1(config-router)#eigrp stub receive-only
*Mar 18 12:52:06.603: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 1.1.1.2 (Serial3/0) is down: peer info changed


*Mar 18 12:52:06.959: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 1.1.1.2 (Serial3/0) is up: new adjacency
R1(config-router)#end

R2#show ip route eigrp
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

      13.0.0.0/22 is subnetted, 1 subnets
D        13.0.0.0 [90/2297856] via 2.1.1.2, 00:11:12, Serial3/1


R3#show ip route eigrp
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

D     1.0.0.0/8 [90/2681856] via 2.1.1.1, 00:11:55, Serial3/1
      13.0.0.0/8 is variably subnetted, 9 subnets, 3 masks
D        13.0.0.0/22 is a summary, 00:14:44, Null0
D     20.0.0.0/8 [90/2172416] via 2.1.1.1, 00:11:55, Serial3/1

(after configure EIGRP STUB receive only on route 1. router 1 preventing all the routes
but router 3 learn all the routes from route 2)

  • remove previous configuration of stub and advertise interfaces EIGRP 65001
  • configure default route on router 2 to reach router 4 networks
  • redistribute the static route in eigrp

R1(config)#router eigrp 65001
R1(config-router)#no eigrp stub

R2(config)#  router eigrp 65001
R2(config-router)#  no eigrp stub


R3(config)#  router eigrp 65001
R3(config-router)#  no eigrp stub

R2(config)#ip route 0.0.0.0 0.0.0.0 3.1.1.2

R2(config)#router  eigrp 65001
R2(config-router)#redistribute static

R2(config-router)#do sh ip route
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 3.1.1.2 to network 0.0.0.0

S*    0.0.0.0/0 [1/0] via 3.1.1.2
      1.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        1.0.0.0/8 is directly connected, Serial3/0
L        1.1.1.2/32 is directly connected, Serial3/0
      2.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        2.0.0.0/8 is directly connected, Serial3/1
L        2.1.1.1/32 is directly connected, Serial3/1
      3.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        3.0.0.0/8 is directly connected, Serial3/2
L        3.1.1.1/32 is directly connected, Serial3/2
D     10.0.0.0/8 [90/2172416] via 1.1.1.1, 00:04:34, Serial3/0
      12.0.0.0/8 is variably subnetted, 8 subnets, 2 masks
C        12.0.0.0/24 is directly connected, Loopback0
L        12.0.0.1/32 is directly connected, Loopback0
C        12.0.1.0/24 is directly connected, Loopback1
L        12.0.1.1/32 is directly connected, Loopback1
C        12.0.2.0/24 is directly connected, Loopback2
L        12.0.2.1/32 is directly connected, Loopback2
C        12.0.3.0/24 is directly connected, Loopback3
L        12.0.3.1/32 is directly connected, Loopback3
      13.0.0.0/22 is subnetted, 1 subnets
D        13.0.0.0 [90/2297856] via 2.1.1.2, 00:03:48, Serial3/1
      20.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        20.0.0.0/8 is directly connected, FastEthernet0/0
L        20.1.1.1/32 is directly connected, FastEthernet0/0
D     30.0.0.0/8 [90/2172416] via 2.1.1.2, 00:03:48, Serial3/1



R3#show ip route eigrp
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 2.1.1.1 to network 0.0.0.0

D*EX  0.0.0.0/0 [170/2681856] via 2.1.1.1, 00:02:08, Serial3/1
D     1.0.0.0/8 [90/2681856] via 2.1.1.1, 00:04:52, Serial3/1
D     10.0.0.0/8 [90/2684416] via 2.1.1.1, 00:04:52, Serial3/1
      13.0.0.0/8 is variably subnetted, 9 subnets, 3 masks
D        13.0.0.0/22 is a summary, 00:28:54, Null0
D     20.0.0.0/8 [90/2172416] via 2.1.1.1, 00:04:52, Serial3/1

R1#show ip route eigrp
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 1.1.1.2 to network 0.0.0.0

D*EX  0.0.0.0/0 [170/2681856] via 1.1.1.2, 00:02:30, Serial3/0
D     2.0.0.0/8 [90/2681856] via 1.1.1.2, 00:06:00, Serial3/0
      13.0.0.0/22 is subnetted, 1 subnets
D        13.0.0.0 [90/2809856] via 1.1.1.2, 00:05:14, Serial3/0
D     20.0.0.0/8 [90/2172416] via 1.1.1.2, 00:06:00, Serial3/0
D     30.0.0.0/8 [90/2684416] via 1.1.1.2, 00:05:14, Serial3/0



R2(config)#router eigrp 65001
R2(config-router)#eigrp stub static
R2(config-router)#end

*Mar 18 13:10:20.819: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 2.1.1.2 (Serial3/1) is down: peer info changed

*Mar 18 13:10:20.847: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 1.1.1.1 (Serial3/0) is down: peer info changed

*Mar 18 13:10:21.575: %DUAL-5-NBRCHANGE: EIGRP-IPv4 65001: Neighbor 1.1.1.1 (Serial3/0) is up: new adjacency

R2(config-router)#end

R1#show ip route eigrp
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 1.1.1.2 to network 0.0.0.0

D*EX  0.0.0.0/0 [170/2681856] via 1.1.1.2, 00:00:48, Serial3/0


R3#show ip route eigrp
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 2.1.1.1 to network 0.0.0.0

D*EX  0.0.0.0/0 [170/2681856] via 2.1.1.1, 00:01:11, Serial3/1
      13.0.0.0/8 is variably subnetted, 9 subnets, 3 masks



R2(config)#router eigrp 65001
R2(config-router)#eigrp stub ?
  connected      Do advertise connected routes
  leak-map       Allow dynamic prefixes based on the leak-map
  receive-only   Set receive only neighbor
  redistributed  Do advertise redistributed routes
  static         Do advertise static routes
  summary        Do advertise summary routes
  <cr>

R2(config-router)#eigrp stub static summary

Success rate is 100 percent (5/5), round-trip min/avg/max = 64/70/84 ms

R1#show ip route eigrp
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 1.1.1.2 to network 0.0.0.0

D*EX  0.0.0.0/0 [170/2681856] via 1.1.1.2, 00:00:41, Serial3/0


R2#ping 14.0.0.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 14.0.0.0, timeout is 2 seconds:
!!!!!

 


 


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