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BGP SVI Routing Configuration

timhudson55
Level 1
Level 1

Hello everyone,

 

Thanks to a very useful community answer (Can BGP be Routed Between 2 SVI's), I now know that I can use SVI's as BGP neighbours. However, I am very new to being hands-on with BGP! Is anyone able to help out a little with some of the commands? I've attached my small topology.

Vlan 151 is for the core site, with VLANs 11 and 12 for sites 1 and 2 respectively. 

 

Any help that someone could provide is greatly appreciated!

 

Kind regards,

Tim

 

 

23 Replies 23

I am not sure what the issue is and suggest that we start from the core switch in looking for problems. As a start I suggest posting the output of these commands from the core:

show ip interface brief

show ip route

show ip bgp neighbor

show ip bgp
HTH

Rick

Et1 Site-1 connected trunk full 10G 10GBASE-SR

 

IP Route

VRF: default
Codes: C - connected, S - static, K - kernel,
       O - OSPF, IA - OSPF inter area, E1 - OSPF external type 1,
       E2 - OSPF external type 2, N1 - OSPF NSSA external type 1,
       N2 - OSPF NSSA external type2, B - BGP, B I - iBGP, B E - eBGP,
       R - RIP, I L1 - IS-IS level 1, I L2 - IS-IS level 2,
       O3 - OSPFv3, A B - BGP Aggregate, A O - OSPF Summary,
       NG - Nexthop Group Static Route, V - VXLAN Control Service,
       DH - DHCP client installed default route, M - Martian,
       DP - Dynamic Policy Route, L - VRF Leaked,
       RC - Route Cache Route

Gateway of last resort:
 S        0.0.0.0/0 is directly connected, Vlan151

 C        10.15.1.0/24 is directly connected, Vlan151
 C        10.16.253.0/24 is directly connected, Vlan253
 C        10.101.1.0/30 is directly connected, Vlan101

BGP Neighbours:

BGP neighbor is 10.101.1.2, remote AS 11, external link
  BGP version 4, remote router ID 0.0.0.0, VRF default
  Negotiated BGP version 0
  Member of update group 1
  Last read never, last write never
  Hold time is 180, keepalive interval is 60 seconds
  Configured hold time is 180, keepalive interval is 60 seconds
  Connect timer is active, time left: 00:01:46
  Connection interval is 148 seconds
  Failed connection attempts is 17
  Idle-restart timer is inactive
  BGP state is Active
  Number of transitions to established: 0
  Last state was Active
  Last event was Start
  Neighbor Capabilities:
    Multiprotocol IPv4 Unicast: advertised
    Four Octet ASN: advertised
    Route Refresh: advertised
    Send End-of-RIB messages: advertised
  Restart timer is inactive
  End of rib timer is inactive
  Message Statistics:
    InQ depth is 0
    OutQ depth is 0
                         Sent      Rcvd
    Opens:                  0         0
    Notifications:          0         0
    Updates:                0         0
    Keepalives:             0         0
    Route-Refresh:          0         0
    Total messages:         0         0
  Prefix Statistics:
                         Sent      Rcvd     Best Paths     Best ECMP Paths
    IPv4 Unicast:           0         0              0
       0
    IPv6 Unicast:           0         0              0
       0
    IPv4 SR-TE:             0         0              0
       0
    IPv6 SR-TE:             0         0              0
       0
  Inbound updates dropped by reason:
    AS path loop detection: 0
    Enforced First AS: 0
    Originator ID matches local router ID: 0
    Nexthop matches local IP address: 0
    Unexpected IPv6 nexthop for IPv4 routes: 0
    Nexthop invalid for single hop eBGP: 0
  Inbound updates with attribute errors:
    Resulting in removal of all paths in update (treat-as-withdraw): 0
    Resulting in AFI/SAFI disable: 0
    Resulting in attribute ignore: 0
  Inbound paths dropped by reason:
    IPv4 labeled-unicast NLRIs dropped due to excessive labels: 0
    IPv6 labeled-unicast NLRIs dropped due to excessive labels: 0
  Outbound paths dropped by reason:
    IPv4 local address not available: 0
    IPv6 local address not available: 0
    Inbound policy
    Outbound policy
Local AS is 151, local router ID 10.101.1.1
TTL is 1
Local TCP address is 10.101.1.1
Remote TCP address is 10.101.1.2, remote port is 179
Auto-Local-Addr is disabled
BGP routing table information for VRF default
Router identifier 10.101.1.1, local AS number 151
Route status codes: s - suppressed, * - valid, > - active, # - not installed, E - ECMP head, e - ECMP
                    S - Stale, c - Contributing to ECMP, b - backup, L - labeled-unicast
Origin codes: i - IGP, e - EGP, ? - incomplete
AS Path Attributes: Or-ID - Originator ID, C-LST - Cluster List, LL Nexthop - Link Local Nexthop

         Network                Next Hop            Metric  LocPref Weight  Path
 * >     10.15.1.0/24           -                     1       0       -       i
 * >     10.101.1.0/30          -                     1       0       -       i

Hello,

 

Apologies for the delay, I went to sleep! I cannot ping from 10.101.1.2 from the core switch. I'll post the configs and bgp sumarries for you.

 

Core Switch

Running Config:

vlan 151
!
vlan 253
   name IB-MGMT
!
vrf instance OOB-MGMT
   rd 100:100
!
interface Ethernet1
   description Site-1
   switchport mode trunk
!
interface Ethernet2
   description Site-2
   switchport mode trunk
!
interface Ethernet25
   speed forced 1000full
   switchport access vlan 151
   switchport mode trunk
!
interface Ethernet26
   speed forced 1000full
   switchport access vlan 151
   switchport mode trunk
!
interface Management1
   description OOB-MGMT
   vrf OOB-MGMT
   ip address 10.12.51.20/24
!
interface Vlan101
   description TRANSIT-SITE-1
   no autostate
   ip address 10.101.1.1/30
!
interface Vlan151
   no autostate
   ip address 10.15.1.254/24
!
interface Vlan252
   vrf OOB-MGMT
!
interface Vlan253
   description IB-MGMT
   no autostate
   ip address 10.16.253.101/24
!
interface Vlan254
!
ip routing
no ip routing vrf OOB-MGMT
!
ip route 0.0.0.0/0 10.15.1.254
ip route vrf OOB-MGMT 0.0.0.0/0 10.12.51.254
!
router bgp 151
   neighbor 10.101.1.1 maximum-routes 12000
   neighbor 10.101.1.2 remote-as 11
   neighbor 10.101.1.2 maximum-routes 12000
   !
   address-family ipv4
      neighbor 10.101.1.2 activate
      network 10.15.1.0/24
      network 10.101.1.0/30
!
end

Show IP BGP summary:

BGP summary information for VRF default
Router identifier 10.101.1.1, local AS number 151
Neighbor Status Codes: m - Under maintenance
  Neighbor         V  AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   PfxRcd PfxAcc
  10.101.1.2       4  11                 0         0    0    0 00:10:12 Active

Site 1:

Running Config

vlan 11
!
vlan 253
   name IB-MGMT
!
vrf instance OOB-MGMT
   rd 100:100
!
interface Ethernet1
   switchport access vlan 11
!
interface Ethernet2
   switchport access vlan 11
!
interface Ethernet30
   description uplink-to-spine
   switchport mode trunk
!
interface Management1
   description OOB-MGMT
   vrf OOB-MGMT
   ip address 10.12.51.22/24
!
interface Vlan11
   no autostate
   ip address 10.1.1.254/24
!
interface Vlan101
   description TRANSIT-SITE-1
   no autostate
   ip address 10.101.1.2/30
!
interface Vlan253
   description IB-MGMT
   no autostate
   ip address 10.16.253.1/24
!
interface Vlan1001
   description TRANSIT-SITE-1
!
ip routing
no ip routing vrf OOB-MGMT
!
ip route vrf OOB-MGMT 0.0.0.0/0 10.12.51.254
!
router bgp 11
   neighbor 10.101.1.1 remote-as 151
   !
   address-family ipv4
      neighbor 10.101.1.1 activate
      network 10.1.1.0/24
      network 10.101.1.0/30
!
end

Show IP BGP Summary:

BGP summary information for VRF default
Router identifier 10.101.1.2, local AS number 11
Neighbor Status Codes: m - Under maintenance
  Neighbor         V  AS           MsgRcvd   MsgSent  InQ OutQ  Up/Down State   PfxRcd PfxAcc
  10.101.1.1       4  151                0         0    0    0 00:08:48 


Please let me know if you need any other bits.
Many thanks!
Tim

 

If you cannot ping 10.101.1.2 from the core switch then you need to fix that before BGP will work. 

 

If you do a

sh vlan

on both switches is vlan 101 in the output ? 

 

Jon

VLAN  Name                             Status    Ports
----- -------------------------------- --------- -------------------------------
1     default                          active    Et1, Et25, Et26
151   VLAN0151                         active    Cpu, Et1, Et25, Et26
253   IB-MGMT                          active    Cpu, Et1, Et25, Et26

^^ Core

 

VLAN  Name                             Status    Ports
----- -------------------------------- --------- -------------------------------
1     default                          active    Et29, Et30
11    VLAN0011                         active    Cpu, Et1, Et2, Et29, Et30
253   IB-MGMT                          active    Cpu, Et29, Et30

^ site 1

 

So you need to create the vlan in the vlan database on both switches. 

 

Then you should be able to ping. 

 

Jon

Oh wow it works!!!!

 

Thankyou very much!

Hi friend, 
the BGP not advertise the prefix until you config one of following:-

1- redistribute the connect 
2- network prefix 



if the bgp neighbor not establish please use 

ebgp multi-hop

 
I know it connect with same VLAN but the TTL must decrease in one SW and hence the BGP is drop.

Hello

That will not work, for the bgp peering to establish the peers or the transit path for the peering address need to share the same subnet

 

Example

CORE-SWITCH
 int vlan xx
ip address 10.15.1.252 255.255.252

router bgp 151

 neighbour 10.15.1.252 remote-as 11


SITE-1-SWITCH
 int vlan xx
ip address 10.15.1.253 255.255.252
router bgp 11

 neighbour 10.15.1.253 remote-as 151

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul
Review Cisco Networking for a $25 gift card