02-08-2022 07:33 AM - last edited on 02-14-2022 05:40 PM by Translator
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
Solved! Go to Solution.
02-08-2022 01:09 PM - last edited on 02-14-2022 05:36 PM by Translator
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
02-09-2022 12:53 AM
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
02-09-2022 12:44 AM
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
02-09-2022 01:12 AM - last edited on 02-14-2022 05:37 PM by Translator
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
02-09-2022 01:15 AM
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
02-09-2022 01:24 AM
So you need to create the vlan in the vlan database on both switches.
Then you should be able to ping.
Jon
02-09-2022 01:53 AM
Oh wow it works!!!!
Thankyou very much!
02-08-2022 01:30 PM - last edited on 02-14-2022 05:38 PM by Translator
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.
02-08-2022 08:04 AM - last edited on 02-14-2022 05:39 PM by Translator
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
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