Skip to main content

BGP Local preference configuration

Image
By Edgar C Francis Internetworks



BGP Local preference (Local_Pref) Path attribute gives the router inside a single autonomous system a value that they can set per-route and advertise to all iBGP routers inside the autonomous system, so that all routers in the autonomous system agree about which routers is the best exit point for packet destined for that prefix.


  • Local preference (Local_Pref) is the second BGP attribute.
  • We can use the local preference to choose the outbound external BGP path.
  • Local preference is sent to all internal BGP (iBGP) routers in our autonomous system.
  • Local preference (Local_Pref) is not exchanged between external BGP routers.
  • It’s a well-known and discretionary BGP attribute.
  • Default value is 100.
  • The path with the highest local preference is desirable 


Topology:-


TASK: To reach 50.1.1.1, 15.0.0.1 network router 2 and router 3 using 3.1.1.2 path ( AS 65144) because it has less numbers of autonomous system. but as per our requirement we need router use 1.1.1.1 interface to reach all the networks, to manipulate the path we use local_pref
  • configure the topology as per the diagram.
  • configure iBGP and eBGP peering using directly connected interfaces.
  • advertise all the networks as per the topology.
  • configure router 2 exit point for autonomous system of 65123.
  • make sure router 2 reach all the network via router 1.

ROUTER-1(config)#Interface fastethernet 0/0
ROUTER-1(config-if)#Ip address 10.1.1.1   255.0.0.0
ROUTER-1(config-if)#No shutdown
ROUTER-1(config-if)#No keepalive
ROUTER-1(config-if)#Exit

ROUTER-1(config)#Interface serial 3/0
ROUTER-1(config-if)#Ip address  1.1.1.1 255.0.0.0
ROUTER-1(config-if)#No shutdown

ROUTER-1(config-if)#Exit
ROUTER-1(config)#Interface serial 3/3
ROUTER-1(config-if)#Ip address  4.4.4.2 255.0.0.0
ROUTER-1(config-if)#No shutdown
ROUTER-1(config-if)#Exit

ROUTER-1(config)#Interface loopback 0
ROUTER-1(config-if)#Ip address 11.0.0.1 255.255.255.0
ROUTER-1(config-if)#Exit


ROUTER-2(config)#Interface fastethernet 0/0
ROUTER-2(config-if)#Ip address 20.1.1.1   255.0.0.0
ROUTER-2(config-if)#No shutdown
ROUTER-2(config-if)#No keepalive
ROUTER-2(config-if)#Exit

ROUTER-2(config)#Interface serial 3/0
ROUTER-2(config-if)#Ip address  1.1.1.2 255.0.0.0
ROUTER-2(config-if)#No shutdown
ROUTER-2(config-if)#Exit

ROUTER-2(config)#Interface serial 3/1
ROUTER-2(config-if)#Ip address  2.2.2.1 255.0.0.0
ROUTER-2(config-if)#No shutdown
ROUTER-2(config-if)#Exit

ROUTER-2(config)#Interface loopback  1
ROUTER-2(config-if)#Ip address 12.0.1.1 255.255.255.0
ROUTER-2(config-if)#Exit


ROUTER-3(config)#Interface fastethernet 0/0
ROUTER-3(config-if)#Ip address 30.1.1.1   255.0.0.0
ROUTER-3(config-if)#No shutdown
ROUTER-3(config-if)#No keepalive
ROUTER-3(config-if)#Exit

ROUTER-3(config)#Interface serial 3/1
ROUTER-3(config-if)#Ip address  2.2.2.2 255.0.0.0
ROUTER-3(config-if)#No shutdown
ROUTER-3(config-if)#Exit

ROUTER-3(config)#Interface serial 3/2
ROUTER-3(config-if)#Ip address  3.3.3.1 255.0.0.0
ROUTER-3(config-if)#No shutdown
ROUTER-3(config-if)#Exit
ROUTER-3(config)#

ROUTER-3(config)#Interface loopback 0
ROUTER-3(config-if)#Ip address 13.0.0.1 255.255.255.0
ROUTER-3(config-if)#Exit


ROUTER-4(config)#Interface fastethernet 0/0
ROUTER-4(config-if)#Ip address 40.1.1.1   255.0.0.0
ROUTER-4(config-if)#No shutdown
ROUTER-4(config-if)#No keepalive
ROUTER-4(config-if)#Exit

ROUTER-4(config)#Interface serial 3/2
ROUTER-4(config-if)#Ip address  3.3.3.2 255.0.0.0
ROUTER-4(config-if)#No shutdown
ROUTER-4(config-if)#Exit

ROUTER-4(config)#Interface serial 3/4
ROUTER-4(config-if)#Ip address  5.5.5.2 255.0.0.0
ROUTER-4(config-if)#No shutdown
ROUTER-4(config-if)#Exit

ROUTER-4(config)#Interface serial 3/3
ROUTER-4(config-if)#Ip address  4.4.4.1 255.0.0.0
ROUTER-4(config-if)#No shutdown
ROUTER-4(config-if)#Exit


ROUTER-5(config)#Interface fastethernet 0/0
ROUTER-5(config-if)#Ip address 50.1.1.1   255.0.0.0
ROUTER-5(config-if)#No shutdown
ROUTER-5(config-if)#No keepalive
ROUTER-5(config-if)#Exit

ROUTER-5(config)#Interface serial 3/4
ROUTER-5(config-if)#Ip address  5.5.5.1 255.0.0.0
ROUTER-5(config-if)#No shutdown
ROUTER-5(config-if)#Exit

ROUTER-5(config)#Interface loopback 0
ROUTER-5(config-if)#Ip address 15.0.0.1 255.255.255.0
ROUTER-5(config-if)#Exit


ROUTER-1(config)#router bgp 65111
ROUTER-1(config-router)#neighbor 1.1.1.2 remote-as 65123
ROUTER-1(config-router)#neighbor 1.1.1.2 remote-as 65144
ROUTER-1(config-router)#neighbor 4.4.4.1 remote-as 65144
ROUTER-1(config-router)#network 10.0.0.0
ROUTER-1(config-router)#network 1.0.0.0
ROUTER-1(config-router)#network 4.0.0.0
ROUTER-1(config-router)#network 11.0.0.0 mask 255.255.255.0
ROUTER-1(config-router)#no auto-summary
ROUTER-1(config-router)#no synchronization
ROUTER-1(config-router)#exit

*Nov 30 00:55:16.523: %BGP-5-ADJCHANGE: neighbor 1.1.1.2 Up

ROUTER-2(config)#router bgp 65123

ROUTER-2(config-router)#neighbor 1.1.1.1 remote-as 65111
ROUTER-2(config-router)#neighbor 1.1.1.1 remote-as 6511
ROUTER-2(config-router)#neighbor 2.2.2.2 remote-as 65123
ROUTER-2(config-router)#network 20.1.1.1
ROUTER-2(config-router)#network 2.1.1.1
ROUTER-2(config-router)#network 1.1.1.1
ROUTER-2(config-router)#network 12.0.0.0 mask 255.255.255.0
ROUTER-2(config-router)#no auto-summary
ROUTER-2(config-router)#no synchronization
ROUTER-2(config-router)#exit

ROUTER-2(config)#router bgp 65123
ROUTER-2(config-router)#neighbor 2.2.2.2 next-hop-self
ROUTER-2(config-router)#exit

ROUTER-2(config)#do clear ip bgp * soft


*Nov 30 00:59:19.611: %BGP-5-ADJCHANGE: neighbor 1.1.1.1 Up


ROUTER-3(config)#router bgp  65123
ROUTER-3(config-router)#neighbor 2.2.2.1 remote-as 65123
ROUTER-3(config-router)#neighbor 2.2.2.1 remote-as 65144
ROUTER-3(config-router)#neighbor 3.3.3.2 remote-as 65144
ROUTER-3(config-router)#network 2.0.0.0
ROUTER-3(config-router)#network 3.0.0.0
ROUTER-3(config-router)#network 30.0.0.0
ROUTER-3(config-router)#network 13.0.0.0 mask 255.255.255.0
ROUTER-3(config-router)#no auto-summary
ROUTER-3(config-router)#no synchronization
ROUTER-3(config-router)#exit

*Nov 30 01:10:34.847: %BGP-5-ADJCHANGE: neighbor 3.3.3.2 Up


ROUTER-3(config)#router bgp 65123
ROUTER-3(config-router)#neighbor 2.2.2.1 next-hop-self
ROUTER-3(config-router)#exit

*Nov 30 01:08:47.059: %BGP-5-ADJCHANGE: neighbor 2.2.2.1 Up

ROUTER-4(config)#router bgp 65144
ROUTER-4(config-router)#neighbor 3.3.3.1 remote-as 65123
ROUTER-4(config-router)#neighbor 4.4.4.2 remote-as 65111
ROUTER-4(config-router)#neighbor 5.5.5.1 remote-as 65155
ROUTER-4(config-router)#network 40.0.0.0
ROUTER-4(config-router)#network 4.0.0.0
ROUTER-4(config-router)#network 5.0.0.0
ROUTER-4(config-router)#network 3.0.0.0
ROUTER-4(config-router)#network 14.0.0.0 mask 255.255.255.0
ROUTER-4(config-router)#no auto-summary
ROUTER-4(config-router)#no synchronization
ROUTER-4(config-router)#exit

*Nov 30 01:17:25.667: %BGP-5-ADJCHANGE: neighbor 5.5.5.1 Up
*Nov 30 01:10:34.827: %BGP-5-ADJCHANGE: neighbor 3.3.3.1 Up
*Nov 30 01:10:54.627: %BGP-5-ADJCHANGE: neighbor 4.4.4.2 Up

ROUTER-5(config)#router bgp 65155
ROUTER-5(config-router)#neighbor 5.5.5.2 remote-as 65144
ROUTER-5(config-router)#network 50.0.0
ROUTER-5(config-router)#network 50.0.0.0
ROUTER-5(config-router)#network 5.0.0.0
ROUTER-5(config-router)#network 15.0.0.0 mask 255.255.255.0
ROUTER-5(config-router)#no auto-summary
ROUTER-5(config-router)#no synchronization
ROUTER-5(config-router)#exit

*Nov 30 01:17:24.823: %BGP-5-ADJCHANGE: neighbor 5.5.5.2 Up

ROUTER-1#show ip route bgp
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

B     2.0.0.0/8 [20/0] via 1.1.1.2, 00:33:49
B     3.0.0.0/8 [20/0] via 1.1.1.2, 00:33:19
B     5.0.0.0/8 [20/0] via 4.4.4.1, 00:30:49
      13.0.0.0/24 is subnetted, 1 subnets
B        13.0.0.0 [20/0] via 1.1.1.2, 00:33:19
      14.0.0.0/24 is subnetted, 1 subnets
B        14.0.0.0 [20/0] via 4.4.4.1, 00:30:49
      15.0.0.0/24 is subnetted, 1 subnets
B        15.0.0.0 [20/0] via 4.4.4.1, 00:25:00
B     20.0.0.0/8 [20/0] via 1.1.1.2, 00:07:25
B     30.0.0.0/8 [20/0] via 1.1.1.2, 00:09:46
B     40.0.0.0/8 [20/0] via 4.4.4.1, 00:31:20
B     50.0.0.0/8 [20/0] via 4.4.4.1, 00:25:00


ROUTER-2#show ip route bgp
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

B     3.0.0.0/8 [200/0] via 2.2.2.2, 00:33:53
B     4.0.0.0/8 [20/0] via 1.1.1.1, 00:43:44
B     5.0.0.0/8 [200/0] via 2.2.2.2, 00:23:08
B     10.0.0.0/8 [20/0] via 1.1.1.1, 00:43:44
      11.0.0.0/24 is subnetted, 1 subnets
B        11.0.0.0 [20/0] via 1.1.1.1, 00:43:44
      13.0.0.0/24 is subnetted, 1 subnets
B        13.0.0.0 [200/0] via 2.2.2.2, 00:33:40
      14.0.0.0/24 is subnetted, 1 subnets
B        14.0.0.0 [200/0] via 2.2.2.2, 00:23:08
      15.0.0.0/24 is subnetted, 1 subnets
B        15.0.0.0 [200/0] via 2.2.2.2, 00:23:08
B     30.0.0.0/8 [200/0] via 2.2.2.2, 00:09:55
B     40.0.0.0/8 [200/0] via 2.2.2.2, 00:23:08
B     50.0.0.0/8 [200/0] via 2.2.2.2, 00:23:08


ROUTER-3#show ip route bgp
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

B     1.0.0.0/8 [200/0] via 2.2.2.1, 00:24:04
B     4.0.0.0/8 [20/0] via 3.3.3.2, 00:31:33
B     5.0.0.0/8 [20/0] via 3.3.3.2, 00:31:03
B     10.0.0.0/8 [200/0] via 2.2.2.1, 00:24:04
      11.0.0.0/24 is subnetted, 1 subnets
B        11.0.0.0 [200/0] via 2.2.2.1, 00:24:04
      14.0.0.0/24 is subnetted, 1 subnets
B        14.0.0.0 [20/0] via 3.3.3.2, 00:31:03
      15.0.0.0/24 is subnetted, 1 subnets
B        15.0.0.0 [20/0] via 3.3.3.2, 00:25:13
B     20.0.0.0/8 [200/0] via 2.2.2.1, 00:07:39
B     40.0.0.0/8 [20/0] via 3.3.3.2, 00:31:33
B     50.0.0.0/8 [20/0] via 3.3.3.2, 00:25:13



ROUTER-4# show ip route bgp
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

B     1.0.0.0/8 [20/0] via 4.4.4.2, 00:32:18
B     2.0.0.0/8 [20/0] via 3.3.3.1, 00:32:38
B     10.0.0.0/8 [20/0] via 4.4.4.2, 00:32:18
      11.0.0.0/24 is subnetted, 1 subnets
B        11.0.0.0 [20/0] via 4.4.4.2, 00:32:18
      13.0.0.0/24 is subnetted, 1 subnets
B        13.0.0.0 [20/0] via 3.3.3.1, 00:32:38
      15.0.0.0/24 is subnetted, 1 subnets
B        15.0.0.0 [20/0] via 5.5.5.1, 00:25:16
B     20.0.0.0/8 [20/0] via 3.3.3.1, 00:07:41
B     30.0.0.0/8 [20/0] via 3.3.3.1, 00:10:03
B     50.0.0.0/8 [20/0] via 5.5.5.1, 00:25:16


ROUTER-5#show ip route bgp
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

B     1.0.0.0/8 [20/0] via 5.5.5.2, 00:25:51
B     2.0.0.0/8 [20/0] via 5.5.5.2, 00:25:51
B     3.0.0.0/8 [20/0] via 5.5.5.2, 00:25:51
B     4.0.0.0/8 [20/0] via 5.5.5.2, 00:25:51
B     10.0.0.0/8 [20/0] via 5.5.5.2, 00:25:51
      11.0.0.0/24 is subnetted, 1 subnets
B        11.0.0.0 [20/0] via 5.5.5.2, 00:25:51
      13.0.0.0/24 is subnetted, 1 subnets
B        13.0.0.0 [20/0] via 5.5.5.2, 00:25:51
      14.0.0.0/24 is subnetted, 1 subnets
B        14.0.0.0 [20/0] via 5.5.5.2, 00:25:51
B     20.0.0.0/8 [20/0] via 5.5.5.2, 00:07:15
B     30.0.0.0/8 [20/0] via 5.5.5.2, 00:10:07
B     40.0.0.0/8 [20/0] via 5.5.5.2, 00:25:51
ROUTER-2#show ip bgp
BGP table version is 22, local router ID is 12.0.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
              x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found

     Network          Next Hop            Metric LocPrf Weight Path
 r>  1.0.0.0          1.1.1.1                  0             0 65111 i
 r>i 2.0.0.0          2.2.2.2                  0    100      0 i
 *>i 3.0.0.0          2.2.2.2                  0    100      0 i
 * i 4.0.0.0          2.2.2.2                  0    100      0 65144 i
 *>                   1.1.1.1                  0             0 65111 i
 *   5.0.0.0          1.1.1.1                                0 65111 65144 i
 *>i                  2.2.2.2                  0    100      0 65144 i
 *>  10.0.0.0         1.1.1.1                  0             0 65111 i
 *>  11.0.0.0/24      1.1.1.1                  0             0 65111 i
 *>i 13.0.0.0/24      2.2.2.2                  0    100      0 i
 *   14.0.0.0/24      1.1.1.1                                0 65111 65144 i
 *>i                  2.2.2.2                  0    100      0 65144 i
 *>i 15.0.0.0/24      2.2.2.2                  0    100      0 65144 65155 i
 *                    1.1.1.1                                0 65111 65144 65155 i
     Network          Next Hop            Metric LocPrf Weight Path
 *>  20.0.0.0         0.0.0.0                  0         32768 i
 *>i 30.0.0.0         2.2.2.2                  0    100      0 i
 *   40.0.0.0         1.1.1.1                                0 65111 65144 i
 *>i                  2.2.2.2                  0    100      0 65144 i
 *>i 50.0.0.0         2.2.2.2                  0    100      0 65144 65155 i
 *                    1.1.1.1                                0 65111 65144 65155 i

ROUTER-2#traceroute 50.1.1.1
Type escape sequence to abort.
Tracing the route to 50.1.1.1
VRF info: (vrf in name/id, vrf out name/id)
  1 2.2.2.2 140 msec 76 msec 100 msec
  2 3.3.3.2 128 msec 136 msec 200 msec
  3 5.5.5.1 [AS 65144] 300 msec 252 msec 172 msec


( configuring local pref  on router 2 )

ROUTER-2(config)#router bgp 65123
ROUTER-2(config-router)#bgp default local-preference 5000
ROUTER-2(config-router)#exit
ROUTER-2(config)#do clear ip bgp * soft
ROUTER-2(config)#end

ROUTER-2#traceroute 50.1.1.1
Type escape sequence to abort.
Tracing the route to 50.1.1.1
VRF info: (vrf in name/id, vrf out name/id)
  1 1.1.1.1 [AS 65111] 48 msec 48 msec 100 msec
  2 4.4.4.1 [AS 65111] 116 msec 128 msec 128 msec
  3 5.5.5.1 [AS 65144] 200 msec 180 msec 248 msec


ROUTER-2#show ip route bgp

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

B     3.0.0.0/8 [200/0] via 2.2.2.2, 00:03:05
B     4.0.0.0/8 [20/0] via 1.1.1.1, 00:03:05
B     5.0.0.0/8 [20/0] via 1.1.1.1, 00:03:05
B     10.0.0.0/8 [20/0] via 1.1.1.1, 01:00:29
      11.0.0.0/24 is subnetted, 1 subnets
B        11.0.0.0 [20/0] via 1.1.1.1, 01:00:29
      13.0.0.0/24 is subnetted, 1 subnets
B        13.0.0.0 [200/0] via 2.2.2.2, 00:03:05
      14.0.0.0/24 is subnetted, 1 subnets
B        14.0.0.0 [20/0] via 1.1.1.1, 00:03:05
      15.0.0.0/24 is subnetted, 1 subnets
B        15.0.0.0 [20/0] via 1.1.1.1, 00:03:05
B     30.0.0.0/8 [200/0] via 2.2.2.2, 00:03:05
B     40.0.0.0/8 [20/0] via 1.1.1.1, 00:03:05
B     50.0.0.0/8 [20/0] via 1.1.1.1, 00:03:05



Labels:

Comments

Post a Comment

Popular posts from this blog

What is Classification and marking? What is IP Precedence and DSCP Values? What is AF and EF?

By Edgar C Francis Internetworks
  Classification and Marking Classification and marking are the processes of identifying the priority of each packet. This is the first step of QOS control and should be done near the source hosts. Classification is the process of identifying and categorising traffic into classes, typically based upon incoming interface IP precedence, DSCP Source or Destination address. Application classification is the most fundamental QOS building block. Without classification, all packets are treated the same.   The table lists the criteria of classification                                  Marking  Marking is the QOS feature component that colours a packet so it can be identified and distinguished from other packets in QOS treatment. Commonly used markers: link-layer: COS (ISL, 802.1q), MPLS EXP bits,...
Post a Comment
Read more

OSPF Tunnels Vs Virtual-links

By Edgar C Francis Internetworks
OSPF VIRTUAL LINKS  An Open Shortest Path First (OSPF) autonomous system has all areas physically connected to the backbone area (Area 0). In some cases, if this is not possible, we can use a virtual link to connect to the backbone (Area 0) through a non-backbone area. We can also use the virtual links to connect two parts of a partitioned backbone (Area 0) through a non-backbone area. The area through which we configure the virtual link, known as a transit area, must have full routing information. Remember, the transit area cannot be a stub area. Virtual link must be configuring both sides with the same area ID and the corresponding virtual link OSPF neighbor router ID. Show IP OSPF neighbors command give you the router ID information. OSPF Transit Area from Tunnel When configuring OSPF with tunnel interfaces as transit areas, there are several important considerations to ensure proper routing functionality. Here's what you need to know: Key Concepts Transit Area : In OS...
Post a Comment
Read more

What is of NBAR (network- based application recognition),classification QOS How to configure NBAR?

By Edgar C Francis Internetworks
 When we implement Quality of Service (QoS ) the first step is classification, by default our router does not care about what kind of IP packets it is. Our router just looks at the routing table to find the correct destination IP address and forwards. When we configure QoS technologies like queuing, policing, or shaping before doing first we have to identify what kind of traffic is running on our routers so we can figure out what kind of application it belongs to. This is classification. What is Quality of Service (QOS)? What is Modular Quality of service CLI (MQC)? What is Classification and marking? What are IP Precedence and DSCP Values? What is AF and EF?     Once we identify our traffic (classify). Now we can mark and apply QoS policy to it. There are a few methods on IOS routers for classification: Header inspection It is a simple classification method and it works really good but has some disadvantages. Let’s say we configure our router all th...
Post a Comment
Read more