BGP IPv6 - Default Route
Default Route
BGP (Border Gateway Protocol) IPv6 Default Route plays a crucial role in efficiently directing IPv6 traffic within a network. It serves as a strategic routing decision, providing a default path for data packets when no specific route matches their destination. This simplifies routing tables, enhances network scalability, and ensures smoother traffic flow in IPv6-enabled environments. By carefully configuring and managing the BGP IPv6 Default Route, network administrators can optimize routing behaviors and contribute to the overall performance and reliability of their IPv6 networks.
Lab:
BGP Topology
Task 1: Configure IPv6 BGP Process for Autonomous
Step 1: In the configuration mode of router configure IPv6 BGP Process by following command:
R1:
interface Ethernet0/0
ipv6 address 12::1/64
no shutdown
exit
ipv6 route 33:0:1::3/64 12::2
ipv6 route 33:0:2::3/64 12::2
ipv6 route 33:0:3::3/64 12::2
ipv6 route 44:0:1::4/64 12::2
ipv6 route 44:0:2::4/64 12::2
ipv6 route 44:0:3::4/64 12::2
exit
R2:
interface Ethernet0/0
ipv6 address 12::2/64
no shutdown
interface Ethernet0/1
ipv6 address 23::2/64
no shutdown
interface Ethernet0/2
ipv6 address 24::2/64
no shutdown
ipv6 route ::/0 12::1
ipv6 unicast-routing
ipv6 router ospf 1
router-id 2.2.2.2
interface Ethernet0/1
ipv6 ospf 1 area 0
interface Ethernet0/2
ipv6 ospf 1 area 0
exit
router bgp 65000
bgp router-id 2.2.2.2
neighbor 23::3 remote-as 65000
neighbor 24::4 remote-as 65200
address-family ipv6
neighbor 23::3 activate
neighbor 24::4 activate
exit
R3:
interface Ethernet0/0
ipv6 address 23::3/64
no shutdown
interface Loopback1
ipv6 address 33:0:1::3/64
interface Loopback2
ipv6 address 33:0:2::3/64
interface Loopback3
ipv6 address 33:0:3::3/64
exit
ipv6 unicast-routing
ipv6 router ospf 1
router-id 3.3.3.3
interface Ethernet0/0
ipv6 ospf 1 area 0
exit
router bgp 65000
bgp router-id 3.3.3.3
neighbor 23::2 remote-as 65000
address-family ipv6
network 33:0:1::0/64
network 33:0:2::0/64
network 33:0:3::0/64
neighbor 23::2 activate
exit
R4:
interface Ethernet 0/0
ipv6 address 24::4/64
no shutdown
interface Loopback1
ipv6 address 44:0:1::4/64
interface Loopback2
ipv6 address 44:0:2::4/64
interface Loopback3
ipv6 address 44:0:3::4/64
exit
ipv6 unicast-routing
ipv6 router ospf 1
router-id 4.4.4.4
interface Ethernet0/0
ipv6 ospf 1 area 0
exit
router bgp 65200
bgp router-id 4.4.4.4
neighbor 24::2 remote-as 65000
address-family ipv6
network 44:0:1::0/64
network 44:0:2::0/64
network 44:0:3::0/64
neighbor 24::2 activate
exit
Step 2: Verify IPv6 BGP routes by following command
R2 is learning the loopbacks from R3 and R4.
R2#show bgp ipv6 unicast
BGP table version is 7, local router ID is 2.2.2.2
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
*>i 33:0:1::/64 23::3 0 100 0 i
*>i 33:0:2::/64 23::3 0 100 0 i
*>i 33:0:3::/64 23::3 0 100 0 i
*> 44:0:1::/64 24::4 0 0 65200 i
*> 44:0:2::/64 24::4 0 0 65200 i
*> 44:0:3::/64 24::4 0 0 65200 i
R2 has a default route towards R1.
The goal is to announce default route in BGP. Redistribute static should be
enough to announce the default route.
R2(config)#router bgp 65000
R2(config-router)address-family ipv6
R2(config-router-af)#redistribute static
R4#show bgp ipv6 unicast
BGP table version is 7, local router ID is 4.4.4.4
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
*> 33:0:1::/64 24::2 0 65000 i
*> 33:0:2::/64 24::2 0 65000 i
*> 33:0:3::/64 24::2 0 65000 i
*> 44:0:1::/64 :: 0 32768 i
*> 44:0:2::/64 :: 0 32768 i
*> 44:0:3::/64 :: 0 32768 i
Is it in the BGP RIB of R2?
R2#show bgp ipv6 unicast
BGP table version is 7, local router ID is 2.2.2.2
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
*>i 33:0:1::/64 23::3 0 100 0 i
*>i 33:0:2::/64 23::3 0 100 0 i
*>i 33:0:3::/64 23::3 0 100 0 i
*> 44:0:1::/64 24::4 0 0 65200 i
*> 44:0:2::/64 24::4 0 0 65200 i
*> 44:0:3::/64 24::4 0 0 65200 i
It is not. BGP does not redistribute a static default route unless the
default-information command is used. This protects against someone accidentally
redistributing a default route in BGP which could potentially be disastrous.
R2(config)#router bgp 65000
R2(config-router)#address-family ipv6
R2(config-router)#default-information originate
R2(config-router)#exit
R2#show bgp ipv6 unicast
BGP table version is 8, local router ID is 2.2.2.2
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
*> ::/0 12::1 0 32768 ?
*>i 33:0:1::/64 23::3 0 100 0 i
*>i 33:0:2::/64 23::3 0 100 0 i
*>i 33:0:3::/64 23::3 0 100 0 i
*> 44:0:1::/64 24::4 0 0 65200 i
*> 44:0:2::/64 24::4 0 0 65200 i
*> 44:0:3::/64 24::4 0 0 65200 i
R3#show bgp ipv6 unicast
BGP table version is 7, local router ID is 3.3.3.3
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
*>i ::/0 12::1 0 100 0 ?
*> 33:0:1::/64 :: 0 32768 i
*> 33:0:2::/64 :: 0 32768 i
*> 33:0:3::/64 :: 0 32768 i
*>i 44:0:1::/64 24::4 0 100 0 65200 i
*>i 44:0:2::/64 24::4 0 100 0 65200 i
*>i 44:0:3::/64 24::4 0 100 0 65200 i
R4#show bgp ipv6 unicast
BGP table version is 8, local router ID is 4.4.4.4
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
*> ::/0 24::2 0 0 65000 ?
*> 33:0:1::/64 24::2 0 65000 i
*> 33:0:2::/64 24::2 0 65000 i
*> 33:0:3::/64 24::2 0 65000 i
*> 44:0:1::/64 :: 0 32768 i
*> 44:0:2::/64 :: 0 32768 i
*> 44:0:3::/64 :: 0 32768 i
Task 2: Configure IPv6 Default Route in BGP using OSPF
Step 1: In the configuration mode of router configure IPv6 default route by following command:
R2:
router bgp 65000
address-family ipv6
no redistribute static
exit
no ipv6 route ::/0 12::1
interface Ethernet0/0
ipv6 ospf 1 area 0
exit
R1:
ipv6 unicast-routing
ipv6 router ospf 1
router-id 1.1.1.1
interface Ethernet0/0
ipv6 ospf 1 area 0
exit
ipv6 router ospf 1
default-information originate always
exit
Step 2: Verify IPv6 OSPF routes by following command:
There is now a default route learned via Ipv6 OSPF
R2#show ipv6 route ospf
IPv6 Routing Table - default - 14 entries
Codes: C - Connected, L - Local, S - Static, U - Per-user Static route
B - BGP, HA - Home Agent, MR - Mobile Router, R - RIP
H - NHRP, I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea
IS - ISIS summary, D - EIGRP, EX - EIGRP external, NM - NEMO
ND - ND Default, NDp - ND Prefix, DCE - Destination, NDr - Redirect
O - OSPF Intra, OI - OSPF Inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2
ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2, l - LISP
OE2 ::/0 [110/1], tag 1
via FE80::A8BB:CCFF:FE00:100, Ethernet0/0
Step 3: In the configuration mode of router redistribute OSPF into BGP
R2:
router bgp 65000
address-family ipv6
redistribute ospf 1 match external
exit
R2#show bgp ipv6 unicast
BGP table version is 16, local router ID is 2.2.2.2
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
*> ::/0 :: 1 32768 ?
*>i 33:0:1::/64 23::3 0 100 0 i
*>i 33:0:2::/64 23::3 0 100 0 i
*>i 33:0:3::/64 23::3 0 100 0 i
*> 44:0:1::/64 24::4 0 0 65200 i
*> 44:0:2::/64 24::4 0 0 65200 i
*> 44:0:3::/64 24::4 0 0 65200 i
R3#show bgp ipv6 unicast
BGP table version is 9, local router ID is 3.3.3.3
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
*>i ::/0 23::2 1 100 0 ?
*> 33:0:1::/64 :: 0 32768 i
*> 33:0:2::/64 :: 0 32768 i
*> 33:0:3::/64 :: 0 32768 i
*>i 44:0:1::/64 24::4 0 100 0 65200 i
*>i 44:0:2::/64 24::4 0 100 0 65200 i
*>i 44:0:3::/64 24::4 0 100 0 65200 i
R4#show bgp ipv6 unicast
BGP table version is 22, local router ID is 4.4.4.4
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
*> ::/0 24::2 1 0 65000 ?
*> 33:0:1::/64 24::2 0 65000 i
*> 33:0:2::/64 24::2 0 65000 i
*> 33:0:3::/64 24::2 0 65000 i
*> 44:0:1::/64 :: 0 32768 i
*> 44:0:2::/64 :: 0 32768 i
*> 44:0:3::/64 :: 0 32768 i
Thus Default Route in BGP can be spread using static as well as IGP protocols