3750g bgp route issue

[lmanavalan]

hi 

I have issue with bop traffic passing through 3750g. Is there any feature set or sum or platform forwarding I need to enable.

eBGP is establish between 2 router connected via 3750g and and I can see the routes exchanged. But when I traceroute the bop route the switch is for some reason matching the default route and returning it back to the router and route starts to loop.

regrads logesh

[John Blakley]

Is the switch participating using bgp as well? If not, once the switch receives traffic from the router destined for an address, the switch is going to forward it to it's next best hop - which in your case is the default route. If that's the case, and you don't want bgp configured on your switch, you can point your more specific routes with static routes on the switch, or use an igp (ospf/eigrp) on the switch between the router and switch. You'd then redistribute your bgp learned routes on your router into whatever igp you chose.

HTH,

John

[lmanavalan]

Hi

When a Router learns the multihop BGP router and tries to forward the traffic then the devices on the way to the destination does not required to know all the bgp route details?

Below is the diagram and configuration

R1: Configuration

hostname R1
!
interface GigabitEthernet0/1.102
 encapsulation dot1Q 102
 ip address 10.177.56.18 255.255.255.248
 standby 102 ip 10.177.56.17
 standby 102 priority 120
 standby 102 preempt
!
interface GigabitEthernet0/1.108
 encapsulation dot1Q 108
 vrf forwarding mgmt
 ip address 10.157.64.130 255.255.255.128
 standby 108 ip 10.157.64.129
 standby 108 priority 120
 standby 108 preempt
!
!
router ospf 2 vrf mgmt
 router-id 10.157.64.1
 capability vrf-lite
 network 10.157.64.0 0.0.3.255 area 100
 network 10.157.252.74 0.0.0.0 area 0
 default-information originate
!
router ospf 1
 router-id 10.177.56.1
 redistribute connected
 network 10.177.56.0 0.0.3.255 area 0
 default-information originate
!         
router bgp 38456
 bgp router-id 10.177.56.1
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 10.177.56.2 remote-as 38456
 neighbor 10.177.56.2 update-source Loopback0
 neighbor 10.177.57.13 remote-as 132462
 neighbor 10.177.57.13 ebgp-multihop 255
 neighbor 10.177.57.13 update-source Loopback0
 !
 address-family ipv4
  neighbor 10.177.56.2 activate
  neighbor 10.177.56.2 next-hop-self
  neighbor 10.177.56.2 soft-reconfiguration inbound
  neighbor 10.177.57.13 activate
  neighbor 10.177.57.13 send-community both
  neighbor 10.177.57.13 next-hop-self
  neighbor 10.177.57.13 soft-reconfiguration inbound
 exit-address-family
!
!
!         

--------------------------------------------------------
hostname SW1
!
boot-start-marker
boot-end-marker
!
vrf definition mgmt
 description VRF for Management
 rd 1000:1000
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
 exit-address-family
!         
!
system mtu routing 1500
vtp mode transparent
ip routing
!
!
vlan 2-5,10
!
vlan 30
!
vlan 100-105
!
vlan 107
 name MgmtLAN
!
vlan 108-109
!
interface Loopback0
 ip address 10.177.56.5 255.255.255.255
!
interface FastEthernet1/0/5
 description Link to BMobile_wireless_P2P
 switchport access vlan 30
 switchport mode access
!
interface Vlan1
 no ip address
!
interface Vlan30
 ip address 10.177.57.1 255.255.255.240
!
interface Vlan102
 ip address 10.177.56.22 255.255.255.248
!
interface Vlan108
 vrf forwarding mgmt
 ip address 10.157.64.133 255.255.255.128
!
router ospf 1
 router-id 10.177.56.3
 log-adjacency-changes
 network 10.177.56.0 0.0.3.255 area 0
!
ip route 0.0.0.0 0.0.0.0 10.177.56.17
!