Date created: Friday, September 18, 2015 1:35:50 PM. Last modified: Friday, April 6, 2018 5:14:42 PM
Explicit Path for VRF (IOS)
In this example the service provider network is running a full mesh of MPLS-TE tunnels (although no constraints have been configured in this example, they are simply following the IGP shortest path). The customer provides and manages their own CPEs for their L3 VPN and want so stretch layer 2 VLANs between two sites (with dual CPEs and switches) by configuring L2TPv3 tunnels between their own CPEs.
The customer has created an L2TPv3 pseudowire between CPE1 and CPE3 which connects trunk interfaces on SW1 and SW3 and another L2TPv3 pseudowire between CPE2 and CPE4 connecting trunk interfaces on SW2 and SW4. However STP is configured for both test VLANs (10 and 20) to prevent layer 2 loops and within VLAN 10 SW4 is blocking the link to SW2 (which is actually the CPE1 to CPE3 pseudowire) and within VLAN 20 SW3 is blocking the link to SW1 (with is actually the CPE2 to CPE4 pseudowire).
To accommodate this the service provider has nailed up two static MPLS-TE tunnels that specifically route traffic for this customer's VRF around two differ paths on the network. The pseudowire between CPE1 and CPE3 always routes along the explicit path PE1 <-> PE2. The pseudowire between CPE2 and CPE4 always routes along the explicit path PE4 <-> PE3 <-> PE2.
LAN facing interfaces on the CPEs only need support 1500 byte MTU, layer 2 headers are excluded, even when a VLAN tag is included this doesn't need to be acommodated for. WAN facing interfaces on the customer routers (and thus CPE facing interfaces on PE's) need to support an MTU of 1518 + 20 (IPv4) + 4 (L2TPv3) = 1542. PE to PE interfaces need to support 1542 + 2x MPLS labels = 1550 octets.
PE configs with per-VRF tunnels and regular full mesh tunnels for all other traffic:
! PE1 ip vrf CUST1 rd 10.0.0.1:65001 bgp next-hop Loopback12 ! Rewrite the BGP VPNv4 next hop IP to this address on outbound UPDATE messages route-target export 65001:100 route-target import 65001:100 ! mpls traffic-eng tunnels mpls traffic-eng auto-tunnel backup mpls traffic-eng reoptimize timers frequency 30 ! interface Loopback0 ip address 10.0.0.1 255.255.255.255 ip ospf 1 area 0 ! interface Loopback12 ip address 192.168.12.1 255.255.255.255 ! interface Tunnel2 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.2 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel3 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.3 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel4 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.4 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel2100 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.2 tunnel mpls traffic-eng path-option 1 explicit name PE1_TO_PE2 ! interface Tunnel4100 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.4 tunnel mpls traffic-eng path-option 1 explicit name PE1_TO_PE4 ! interface FastEthernet0/0 description Link to PE2 ip address 10.0.12.1 255.255.255.0 ip ospf 1 area 0 mpls traffic-eng tunnels ! interface FastEthernet0/1 description Link to PE4 ip address 10.0.14.1 255.255.255.0 ip ospf 1 area 0 mpls traffic-eng tunnels ! interface FastEthernet1/0 description Link to CPE1 ip vrf forwarding CUST1 ip address 192.168.1.1 255.255.255.252 ! router ospf 1 router-id 10.0.0.1 mpls traffic-eng router-id Loopback0 mpls traffic-eng area 0 ! router bgp 123 template peer-policy iBGP next-hop-self send-community both exit-peer-policy ! template peer-session iBGP remote-as 123 update-source Loopback0 exit-peer-session ! bgp log-neighbor-changes neighbor 10.0.0.2 inherit peer-session iBGP neighbor 10.0.0.3 inherit peer-session iBGP neighbor 10.0.0.4 inherit peer-session iBGP ! address-family vpnv4 neighbor 10.0.0.2 activate neighbor 10.0.0.2 send-community extended neighbor 10.0.0.2 inherit peer-policy iBGP neighbor 10.0.0.3 activate neighbor 10.0.0.3 send-community extended neighbor 10.0.0.3 inherit peer-policy iBGP neighbor 10.0.0.4 activate neighbor 10.0.0.4 send-community extended neighbor 10.0.0.4 inherit peer-policy iBGP exit-address-family ! address-family ipv4 vrf CUST1 redistribute connected neighbor 192.168.1.2 remote-as 65001 neighbor 192.168.1.2 activate neighbor 192.168.1.2 next-hop-self neighbor 192.168.1.2 default-originate exit-address-family ! ! These are the BGP next hops updates in the CUST1 VRF are being re-written to ! on PEs 4 and 2 respectively, 'autoroute announce' is not used becasue this ! is between specific PEs for a specific VRF ! ip route 192.168.42.4 255.255.255.255 Tunnel4100 ip route 192.168.214.2 255.255.255.255 Tunnel2100 ! ip explicit-path name PE1_TO_PE2 enable next-address 10.0.12.2 ! ip explicit-path name PE1_TO_PE4 enable next-address 10.0.14.4 ! mpls ldp router-id Loopback0 force ! PE2 ip vrf CUST1 rd 10.0.0.2:65001 bgp next-hop Loopback214 route-target export 65001:100 route-target import 65001:100 ! mpls traffic-eng tunnels mpls traffic-eng auto-tunnel backup mpls traffic-eng reoptimize timers frequency 30 ! interface Loopback0 ip address 10.0.0.2 255.255.255.255 ip ospf 1 area 0 ! interface Loopback214 ip address 192.168.214.2 255.255.255.255 ! interface Tunnel1 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.1 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel3 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.3 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel4 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.4 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel1100 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.1 tunnel mpls traffic-eng path-option 1 explicit name PE2_TO_PE1 ! interface Tunnel4100 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.4 tunnel mpls traffic-eng path-option 1 explicit name PE2_TO_PE4 ! interface FastEthernet0/0 description Link to PE1 ip address 10.0.12.2 255.255.255.0 ip ospf 1 area 0 mpls traffic-eng tunnels ! interface FastEthernet0/1 description Link to PE3 ip address 10.0.23.2 255.255.255.0 ip ospf 1 area 0 mpls traffic-eng tunnels ! interface FastEthernet1/0 description Link to CPE3 ip vrf forwarding CUST1 ip address 192.168.3.1 255.255.255.252 ! interface FastEthernet1/1 description Link to CPE4 ip vrf forwarding CUST1 ip address 192.168.4.1 255.255.255.252 ! router ospf 1 router-id 10.0.0.2 mpls traffic-eng router-id Loopback0 mpls traffic-eng area 0 ! router bgp 123 template peer-policy iBGP next-hop-self send-community both exit-peer-policy ! template peer-session iBGP remote-as 123 update-source Loopback0 exit-peer-session ! bgp log-neighbor-changes neighbor 10.0.0.1 inherit peer-session iBGP neighbor 10.0.0.3 inherit peer-session iBGP neighbor 10.0.0.4 inherit peer-session iBGP ! address-family ipv4 neighbor 10.0.0.1 activate neighbor 10.0.0.3 activate neighbor 10.0.0.4 activate exit-address-family ! address-family vpnv4 neighbor 10.0.0.1 activate neighbor 10.0.0.1 send-community extended neighbor 10.0.0.3 activate neighbor 10.0.0.3 send-community extended neighbor 10.0.0.3 inherit peer-policy iBGP neighbor 10.0.0.4 activate neighbor 10.0.0.4 send-community extended neighbor 10.0.0.4 inherit peer-policy iBGP exit-address-family ! address-family ipv4 vrf CUST1 redistribute connected neighbor 192.168.2.2 remote-as 65001 neighbor 192.168.2.2 activate neighbor 192.168.2.2 next-hop-self neighbor 192.168.2.2 default-originate neighbor 192.168.3.2 remote-as 65001 neighbor 192.168.3.2 activate neighbor 192.168.3.2 next-hop-self neighbor 192.168.3.2 default-originate neighbor 192.168.4.2 remote-as 65001 neighbor 192.168.4.2 activate neighbor 192.168.4.2 next-hop-self neighbor 192.168.4.2 default-originate exit-address-family ! ip route 192.168.12.1 255.255.255.255 Tunnel1100 ip route 192.168.42.4 255.255.255.255 Tunnel4100 ! ip explicit-path name PE2_TO_PE4 enable next-address 10.0.23.3 next-address 10.0.34.4 ! ip explicit-path name PE2_TO_PE1 enable next-address 10.0.12.1 ! mpls ldp router-id Loopback0 force ! PE4 ip vrf CUST1 rd 10.0.0.4:65001 bgp next-hop Loopback42 route-target export 65001:100 route-target import 65001:100 ! mpls traffic-eng tunnels mpls traffic-eng auto-tunnel backup mpls traffic-eng reoptimize timers frequency 30 ! interface Loopback0 ip address 10.0.0.4 255.255.255.255 ip ospf 1 area 0 ! interface Loopback42 ip address 192.168.42.4 255.255.255.255 ! interface Tunnel1 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.1 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel2 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.2 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel3 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.3 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel1100 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.2 tunnel mpls traffic-eng path-option 1 explicit name PE4_TO_PE1 ! interface Tunnel2100 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.2 tunnel mpls traffic-eng path-option 1 explicit name PE4_TO_PE2 ! interface FastEthernet0/0 description link to PE3 ip address 10.0.34.4 255.255.255.0 ip ospf 1 area 0 mpls traffic-eng tunnels ! interface FastEthernet0/1 description Link to PE1 ip address 10.0.14.4 255.255.255.0 ip ospf 1 area 0 mpls traffic-eng tunnels ! interface FastEthernet1/0 description link to CPE2 ip vrf forwarding CUST1 ip address 192.168.2.1 255.255.255.252 ! router ospf 1 router-id 10.0.0.4 mpls traffic-eng router-id Loopback0 mpls traffic-eng area 0 ! router bgp 123 template peer-policy iBGP next-hop-self send-community both exit-peer-policy ! template peer-session iBGP remote-as 123 update-source Loopback0 exit-peer-session ! bgp log-neighbor-changes neighbor 10.0.0.1 inherit peer-session iBGP neighbor 10.0.0.2 inherit peer-session iBGP neighbor 10.0.0.3 inherit peer-session iBGP ! address-family vpnv4 neighbor 10.0.0.1 activate neighbor 10.0.0.1 send-community extended neighbor 10.0.0.2 activate neighbor 10.0.0.2 send-community extended neighbor 10.0.0.2 inherit peer-policy iBGP neighbor 10.0.0.3 activate neighbor 10.0.0.3 send-community extended neighbor 10.0.0.3 inherit peer-policy iBGP exit-address-family ! address-family ipv4 vrf CUST1 redistribute connected neighbor 192.168.2.2 remote-as 65001 neighbor 192.168.2.2 activate neighbor 192.168.2.2 next-hop-self neighbor 192.168.2.2 default-originate exit-address-family ! ip route 192.168.12.1 255.255.255.255 Tunnel1100 ip route 192.168.214.2 255.255.255.255 Tunnel2100 ! ip explicit-path name PE4_TO_PE2 enable next-address 10.0.34.3 next-address 10.0.23.2 ! ip explicit-path name PE4_TO_PE1 enable next-address 10.0.14.1 ! mpls ldp router-id Loopback0 force ! PE3 mpls traffic-eng tunnels mpls traffic-eng auto-tunnel backup mpls traffic-eng reoptimize timers frequency 30 ! interface Loopback0 ip address 10.0.0.3 255.255.255.255 ip ospf 1 area 0 ! interface Tunnel1 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.1 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel2 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.2 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface Tunnel4 ip unnumbered Loopback0 tunnel mode mpls traffic-eng tunnel destination 10.0.0.4 tunnel mpls traffic-eng autoroute announce tunnel mpls traffic-eng path-option 1 dynamic ! interface FastEthernet0/0 description Link to PE4 ip address 10.0.34.3 255.255.255.0 ip ospf 1 area 0 mpls traffic-eng tunnels ! interface FastEthernet0/1 description Link to PE2 ip address 10.0.23.3 255.255.255.0 ip ospf 1 area 0 mpls traffic-eng tunnels ! router ospf 1 router-id 10.0.0.3 mpls traffic-eng router-id Loopback0 mpls traffic-eng area 0 ! router bgp 123 template peer-policy iBGP next-hop-self send-community both exit-peer-policy ! template peer-session iBGP remote-as 123 update-source Loopback0 exit-peer-session ! bgp log-neighbor-changes neighbor 10.0.0.1 inherit peer-session iBGP neighbor 10.0.0.2 inherit peer-session iBGP neighbor 10.0.0.4 inherit peer-session iBGP ! address-family vpnv4 neighbor 10.0.0.1 activate neighbor 10.0.0.1 send-community extended neighbor 10.0.0.2 activate neighbor 10.0.0.2 send-community extended neighbor 10.0.0.2 inherit peer-policy iBGP neighbor 10.0.0.4 activate neighbor 10.0.0.4 send-community extended neighbor 10.0.0.4 inherit peer-policy iBGP exit-address-family ! mpls ldp router-id Loopback0 force
View from PE2:
PE2#show ip route
10.0.0.0/8 is variably subnetted, 10 subnets, 2 masks
O 10.0.0.1/32 [110/2] via 10.0.0.1, 03:50:12, Tunnel1
C 10.0.0.2/32 is directly connected, Loopback0
O 10.0.0.3/32 [110/2] via 10.0.0.3, 03:42:55, Tunnel3
O 10.0.0.4/32 [110/3] via 10.0.0.4, 03:42:21, Tunnel4
C 10.0.12.0/24 is directly connected, FastEthernet0/0
L 10.0.12.2/32 is directly connected, FastEthernet0/0
O 10.0.14.0/24 [110/2] via 10.0.0.1, 03:50:12, Tunnel1
C 10.0.23.0/24 is directly connected, FastEthernet0/1
L 10.0.23.2/32 is directly connected, FastEthernet0/1
O 10.0.34.0/24 [110/2] via 10.0.0.3, 01:43:13, Tunnel3
192.168.12.0/32 is subnetted, 1 subnets
S 192.168.12.1 is directly connected, Tunnel1100
192.168.42.0/32 is subnetted, 1 subnets
S 192.168.42.4 is directly connected, Tunnel4100
192.168.214.0/32 is subnetted, 1 subnets
C 192.168.214.2 is directly connected, Loopback214
PE2#show int desc
Interface Status Protocol Description
Fa0/0 up up Link to PE1
Fa0/1 up up Link to PE3
Fa1/0 up up Link to CPE3
Fa1/1 up up Link to CPE4
Lo0 up up
Lo214 up up
Tu1 up up
Tu3 up up
Tu4 up up
Tu1100 up up
Tu4100 up up
PE2#show mpls traffic-eng tunnels brief
Signalling Summary:
LSP Tunnels Process: running
Passive LSP Listener: running
RSVP Process: running
Forwarding: enabled
auto-tunnel:
backup Enabled (0 ), id-range:65436-65535
onehop Disabled (0 ), id-range:65336-65435
mesh Disabled (0 ), id-range:64336-65335
Periodic reoptimization: every 30 seconds, next in 28 seconds
Periodic FRR Promotion: Not Running
Periodic auto-tunnel:
backup notinuse scan: every 3600 seconds, next in 475 seconds
Periodic auto-bw collection: every 300 seconds, next in 179 seconds
P2P TUNNELS/LSPs:
TUNNEL NAME DESTINATION UP IF DOWN IF STATE/PROT
PE2_t1 10.0.0.1 - Fa0/0 up/up
PE2_t3 10.0.0.3 - Fa0/1 up/up
PE2_t4 10.0.0.4 - Fa0/0 up/up
PE2_t1100 10.0.0.1 - Fa0/0 up/up
PE2_t4100 10.0.0.4 - Fa0/1 up/up
PE1_t2 10.0.0.2 Fa0/0 - up/up
PE1_t3 10.0.0.3 Fa0/0 Fa0/1 up/up
PE1_t2100 10.0.0.2 Fa0/0 - up/up
PE3_t1 10.0.0.1 Fa0/1 Fa0/0 up/up
PE3_t2 10.0.0.2 Fa0/1 - up/up
PE4_t2 10.0.0.2 Fa0/0 - up/up
PE4_t1100 10.0.0.2 Fa0/0 - up/up
PE4_t2100 10.0.0.2 Fa0/1 - up/up
Displayed 5 (of 5) heads, 2 (of 2) midpoints, 6 (of 6) tails
PE2#show mpls traffic-eng tunnels tu4
Name: PE2_t4 (Tunnel4) Destination: 10.0.0.4
Status:
Admin: up Oper: up Path: valid Signalling: connected
path option 1, type dynamic (Basis for Setup, path weight 2)
Config Parameters:
Bandwidth: 0 kbps (Global) Priority: 7 7 Affinity: 0x0/0xFFFF
Metric Type: TE (default)
AutoRoute: enabled LockDown: disabled Loadshare: 0 [0] bw-based
auto-bw: disabled
Active Path Option Parameters:
State: dynamic path option 1 is active
BandwidthOverride: disabled LockDown: disabled Verbatim: disabled
InLabel : -
OutLabel : FastEthernet0/0, 17
Next Hop : 10.0.12.1
RSVP Signalling Info:
Src 10.0.0.2, Dst 10.0.0.4, Tun_Id 4, Tun_Instance 126
RSVP Path Info:
My Address: 10.0.12.2
Explicit Route: 10.0.12.1 10.0.14.1 10.0.14.4 10.0.0.4
Record Route: NONE
Tspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
RSVP Resv Info:
Record Route: NONE
Fspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
Shortest Unconstrained Path Info:
Path Weight: 2 (TE)
Explicit Route: 10.0.23.2 10.0.23.3 10.0.34.3 10.0.34.4
10.0.0.4
History:
Tunnel:
Time since created: 3 hours, 56 minutes
Time since path change: 1 hours, 57 minutes
Number of LSP IDs (Tun_Instances) used: 126
Current LSP: [ID: 126]
Uptime: 1 hours, 57 minutes
Selection: reoptimization
Prior LSP: [ID: 27]
ID: path option unknown
Removal Trigger: reoptimization completed
PE2#show mpls traffic-eng tunnels tu4100
Name: PE2_t4100 (Tunnel4100) Destination: 10.0.0.4
Status:
Admin: up Oper: up Path: valid Signalling: connected
path option 1, type explicit PE2_TO_PE4 (Basis for Setup, path weight 2)
Config Parameters:
Bandwidth: 0 kbps (Global) Priority: 7 7 Affinity: 0x0/0xFFFF
Metric Type: TE (default)
AutoRoute: disabled LockDown: disabled Loadshare: 0 [0] bw-based
auto-bw: disabled
Active Path Option Parameters:
State: explicit path option 1 is active
BandwidthOverride: disabled LockDown: disabled Verbatim: disabled
InLabel : -
OutLabel : FastEthernet0/1, 24
Next Hop : 10.0.23.3
RSVP Signalling Info:
Src 10.0.0.2, Dst 10.0.0.4, Tun_Id 4100, Tun_Instance 89
RSVP Path Info:
My Address: 10.0.23.2
Explicit Route: 10.0.23.3 10.0.34.3 10.0.34.4 10.0.0.4
Record Route: NONE
Tspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
RSVP Resv Info:
Record Route: NONE
Fspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
Shortest Unconstrained Path Info:
Path Weight: 2 (TE)
Explicit Route: 10.0.23.2 10.0.23.3 10.0.34.3 10.0.34.4
10.0.0.4
History:
Tunnel:
Time since created: 3 hours, 20 minutes
Time since path change: 2 hours, 42 minutes
Number of LSP IDs (Tun_Instances) used: 89
Current LSP: [ID: 89]
Uptime: 2 hours, 42 minutes
PE2#show bgp vpnv4 unicast vrf CUST1
BGP table version is 23, local router ID is 10.0.0.2
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
Route Distinguisher: 10.0.0.2:65001 (default for vrf CUST1)
0.0.0.0 0.0.0.0 0 i
*>i 192.168.1.0/30 192.168.12.1 0 100 0 ?
*>i 192.168.2.0/30 192.168.42.4 0 100 0 ?
* 192.168.3.0/30 192.168.3.2 0 0 65001 ?
*> 0.0.0.0 0 32768 ?
* 192.168.4.0/30 192.168.4.2 0 0 65001 ?
*> 0.0.0.0 0 32768 ?
Ping from SW4 to SW1 on VLAN 10, this runs over the CPE3-to-CPE2 pseudowire and takes the PE2-PE1 per-VRF-MPLS-TE-Tunnel:
Ping from SW3 to SW1 on VLAN 20, this runs over the CPE4-to-CPE2 pseudowire and takes the PE2-PE3-PE4 per-VRF-MPLS-TE-Tunnel:
CPE and switch configs for reference, SW1, CPE1, CPE3, SW3:
! SW1
!
spanning-tree vlan 10 forward-time 4
spanning-tree vlan 10 max-age 6
spanning-tree vlan 10 hello-time 1
spanning-tree vlan 10 priority 8192
spanning-tree vlan 20 forward-time 4
spanning-tree vlan 20 max-age 6
spanning-tree vlan 20 hello-time 1
spanning-tree vlan 20 priority 8192
vtp mode transparent
!
vlan 10,20
!
interface FastEthernet1/0
description Link to CPE1
switchport trunk allowed vlan 1,10,20,1002-1005
switchport mode trunk
spanning-tree vlan 20 cost 500
!
interface FastEthernet1/1
description Link to SW2
switchport trunk allowed vlan 1,10,20,1002-1005
switchport mode trunk
!
interface Vlan10
ip address 192.10.2.1 255.255.255.0
!
interface Vlan20
ip address 192.20.2.1 255.255.255.0
! CPE1
!
xconnect logging pseudowire status
!
pseudowire-class L2TPv3
encapsulation l2tpv3
ip local interface FastEthernet0/0
!
interface FastEthernet0/0
description Link to PE1
ip address 192.168.1.2 255.255.255.252
!
interface FastEthernet0/1
description Xconnect to CPE3
no ip address
no keepalive
xconnect 192.168.3.2 100 encapsulation l2tpv3 pw-class L2TPv3
!
router bgp 65001
bgp log-neighbor-changes
neighbor 192.168.1.1 remote-as 123
!
address-family ipv4
redistribute connected
neighbor 192.168.1.1 activate
neighbor 192.168.1.1 next-hop-self
exit-address-family
! CPE3
!
xconnect logging pseudowire status
!
pseudowire-class L2TPv3
encapsulation l2tpv3
ip local interface FastEthernet0/0
!
interface FastEthernet0/0
description Link to PE2
ip address 192.168.3.2 255.255.255.252
!
interface FastEthernet0/1
description Xconnec to CPE1
no ip address
no keepalive
xconnect 192.168.1.2 100 encapsulation l2tpv3 pw-class L2TPv3
!
router bgp 65001
bgp log-neighbor-changes
neighbor 192.168.3.1 remote-as 123
!
address-family ipv4
redistribute connected
neighbor 192.168.3.1 activate
neighbor 192.168.3.1 next-hop-self
exit-address-family
! SW3
!
spanning-tree vlan 10 forward-time 4
spanning-tree vlan 10 max-age 6
spanning-tree vlan 10 hello-time 1
spanning-tree vlan 20 forward-time 4
spanning-tree vlan 20 max-age 6
spanning-tree vlan 20 hello-time 1
vtp mode transparent
!
vlan 10,20
!
interface FastEthernet1/0
description Link to CPE1
switchport trunk allowed vlan 1,10,20,1002-1005
switchport mode trunk
spanning-tree vlan 20 cost 500
!
interface FastEthernet1/1
description Link to SW2
switchport trunk allowed vlan 1,10,20,1002-1005
switchport mode trunk
!
interface Vlan10
ip address 192.10.2.1 255.255.255.0
!
interface Vlan20
ip address 192.20.2.1 255.255.255.0
SW3#show spanning-tree brief
VLAN10
Spanning tree enabled protocol ieee
Root ID Priority 8192
Address cc09.11f0.0001
Cost 19
Port 41 (FastEthernet1/0)
Hello Time 1 sec Max Age 6 sec Forward Delay 4 sec
Bridge ID Priority 32768
Address cc0b.16f0.0001
Hello Time 1 sec Max Age 6 sec Forward Delay 4 sec
Aging Time 300
Interface Designated
Name Port ID Prio Cost Sts Cost Bridge ID Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
FastEthernet1/0 128.41 128 19 FWD 0 8192 cc09.11f0.0001 128.41
FastEthernet1/1 128.42 128 19 FWD 19 32768 cc0b.16f0.0001 128.42
VLAN20
Spanning tree enabled protocol ieee
Root ID Priority 8192
Address cc09.11f0.0002
Cost 57
Port 42 (FastEthernet1/1)
Hello Time 1 sec Max Age 6 sec Forward Delay 4 sec
Bridge ID Priority 32768
Address cc0b.16f0.0002
Hello Time 1 sec Max Age 6 sec Forward Delay 4 sec
Aging Time 300
Interface Designated
Name Port ID Prio Cost Sts Cost Bridge ID Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
FastEthernet1/0 128.41 128 500 BLK 0 8192 cc09.11f0.0002 128.41
FastEthernet1/1 128.42 128 19 FWD 38 32768 cc0c.18ac.0002 128.42
CPE and switch configs for reference, SW2, CPE2, CPE4, SW4:
! SW2
!
spanning-tree vlan 10 forward-time 4
spanning-tree vlan 10 max-age 6
spanning-tree vlan 10 hello-time 1
spanning-tree vlan 20 forward-time 4
spanning-tree vlan 20 max-age 6
spanning-tree vlan 20 hello-time 1
!
vlan 10,20
!
interface FastEthernet1/0
description Link to CPE2
switchport trunk allowed vlan 1,10,20,1002-1005
switchport mode trunk
spanning-tree vlan 10 cost 500
!
interface FastEthernet1/1
description Link to SW1
switchport trunk allowed vlan 1,10,20,1002-1005
switchport mode trunk
!
interface Vlan10
ip address 192.10.2.2 255.255.255.0
!
interface Vlan20
ip address 192.20.2.2 255.255.255.0
! CPE2
!
xconnect logging pseudowire status
!
pseudowire-class L2TPv3
encapsulation l2tpv3
ip local interface FastEthernet0/0
!
interface FastEthernet0/0
description Link to PE4
ip address 192.168.2.2 255.255.255.252
!
interface FastEthernet0/1
description Xconnect co CPE4
no ip address
no keepalive
xconnect 192.168.4.2 100 encapsulation l2tpv3 pw-class L2TPv3
!
router bgp 65001
bgp log-neighbor-changes
neighbor 192.168.2.1 remote-as 123
!
address-family ipv4
redistribute connected
neighbor 192.168.2.1 activate
neighbor 192.168.2.1 next-hop-self
exit-address-family
! CPE4
!
xconnect logging pseudowire status
!
pseudowire-class L2TPv3
encapsulation l2tpv3
ip local interface FastEthernet0/0
!
interface FastEthernet0/0
description Link to PE2
ip address 192.168.4.2 255.255.255.252
!
interface FastEthernet0/1
description Xconnect to CPE2
no ip address
no keepalive
xconnect 192.168.2.2 100 encapsulation l2tpv3 pw-class L2TPv3
!
router bgp 65001
bgp log-neighbor-changes
neighbor 192.168.4.1 remote-as 123
!
address-family ipv4
redistribute connected
neighbor 192.168.4.1 activate
neighbor 192.168.4.1 next-hop-self
exit-address-family
!
! SW4
!
spanning-tree vlan 10 forward-time 4
spanning-tree vlan 10 max-age 6
spanning-tree vlan 10 hello-time 1
spanning-tree vlan 20 forward-time 4
spanning-tree vlan 20 max-age 6
spanning-tree vlan 20 hello-time 1
vtp mode transparent
!
vlan 10,20
!
interface FastEthernet1/0
description Link to CPE4
switchport trunk allowed vlan 1,10,20,1002-1005
switchport mode trunk
spanning-tree vlan 10 cost 500
!
interface FastEthernet1/1
description Link to SW3
switchport trunk allowed vlan 1,10,20,1002-1005
switchport mode trunk
!
interface Vlan10
ip address 192.10.2.4 255.255.255.0
!
interface Vlan20
ip address 192.20.2.4 255.255.255.0
SW4#show spanning-tree bri
VLAN10
Spanning tree enabled protocol ieee
Root ID Priority 8192
Address cc09.11f0.0001
Cost 38
Port 42 (FastEthernet1/1)
Hello Time 1 sec Max Age 6 sec Forward Delay 4 sec
Bridge ID Priority 32768
Address cc0c.18ac.0001
Hello Time 1 sec Max Age 6 sec Forward Delay 4 sec
Aging Time 300
Interface Designated
Name Port ID Prio Cost Sts Cost Bridge ID Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
FastEthernet1/0 128.41 128 500 BLK 19 32768 cc0a.1170.0001 128.41
FastEthernet1/1 128.42 128 19 FWD 19 32768 cc0b.16f0.0001 128.42
VLAN20
Spanning tree enabled protocol ieee
Root ID Priority 8192
Address cc09.11f0.0002
Cost 38
Port 41 (FastEthernet1/0)
Hello Time 1 sec Max Age 6 sec Forward Delay 4 sec
Bridge ID Priority 32768
Address cc0c.18ac.0002
Hello Time 1 sec Max Age 6 sec Forward Delay 4 sec
Aging Time 300
Interface Designated
Name Port ID Prio Cost Sts Cost Bridge ID Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
FastEthernet1/0 128.41 128 19 FWD 19 32768 cc0a.1170.0002 128.41
FastEthernet1/1 128.42 128 19 FWD 38 32768 cc0c.18ac.0002 128.42
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