ปกติในเครือข่ายขนาดใหญ่ จะแบ่งเครือข่ายออกเป็น Hierarchy เช่น Core, Aggregation หรือ Access โดยอาจแบ่งโดยใช้ IGP (Interior Gateway Protocol) process-id, area หรือแบ่งโดย isis-level. แล้วแต่การออกแบบ จากนั้นก็ Enable MPLS เพื่อให้บริการ MPLS L2VPN, L3VPN เนื่องจากเครือข่ายถูกแบ่งส่วนๆ จึงทำให้ MPLS แบ่งเป็นส่วนๆ ด้วยหรือเรียกว่า MPLS Domain จึงยังไม่สามารถให้บริการ L2VPN หรือ L3VPN แบบ End-to-End ได้ในทันที โดยในบล๊อกนี้ยกตัวอย่างการใช้ BGP LU เข้าช่วย ส่วนจะคอนฟิกอย่างไรนั้น เลื่อนอ่านด้านล่างได้เลยครับ
EVE-NG Network Diagram
ในที่นี้เครือข่ายแบ่งออกเป็น 3 โดเมน โดยใช้ ISIS Level-1, OSPF และ ISIS Level-2 โดย Core อยู่ตรงกลางและ Aggregation อยู่ด้านข้าง ใช้ BGP เพื่อ Advertise Loopback พร้อมกับ Label ของ PE router ข้ามทั้งเครือข่าย พร้อมทั้งให้บริการ L2VPN และ L3VPN
L2VPN แบบ VPWS (Virtual Private Wire Service ) หรือบางทีก็เรียกว่า VLL ( Vitual Lease Line ) จะทำ MS-PW (Multi Segment PseudoWire) ที่ P router ที่เป็น boundary mpls domain
SEAMLESS MPLS with BGP-LU Configuration
ดาวน์โหลดคอนฟิกไฟล์เต็มๆ จากลิ้งนี้ https://drive.google.com/drive/folders/1byPucYTe3rVmfj2j1GCfR8B3rKaGr6Dn?usp=sharing
A:PE1# admin display-config configure #-------------------------------------------------- echo "Connector Configuration" #-------------------------------------------------- port 1/1/c1 description "To_Nokia_P2" connector breakout c1-10g exit no shutdown exit #-------------------------------------------------- echo "Port Configuration" #-------------------------------------------------- port 1/1/c1/1 description "To_Nokia_P2" ethernet exit no shutdown exit #-------------------------------------------------- echo "Router (Network Side) Configuration" #-------------------------------------------------- router Base interface "system" address 10.10.10.1/32 no shutdown exit interface "to_P2" address 192.168.12.1/24 port 1/1/c1/1 no shutdown exit autonomous-system 65000 router-id 10.10.10.1 #-------------------------------------------------- echo "ISIS Configuration" #-------------------------------------------------- isis 0 level-capability level-2 area-id 49.0200 interface "system" level-capability level-2 passive no shutdown exit interface "to_P2" level-capability level-2 interface-type point-to-point no shutdown exit no shutdown exit #-------------------------------------------------- echo "Policy Configuration" #-------------------------------------------------- policy-options begin prefix-list "system-ip" prefix 10.10.10.1/32 exact exit policy-statement "BGP-LU-EXPORT" entry 10 from prefix-list "system-ip" exit action accept exit exit exit commit exit #-------------------------------------------------- echo "LDP Configuration" #-------------------------------------------------- ldp import-pmsi-routes exit interface-parameters interface "to_P2" dual-stack ipv4 no shutdown exit no shutdown exit exit no shutdown exit exit #-------------------------------------------------- echo "BGP Configuration" #-------------------------------------------------- bgp group "Internal" family label-ipv4 export "BGP-LU-EXPORT" peer-as 65000 neighbor 10.10.10.2 exit exit no shutdown exit exit exit all
A:P2# admin display-config configure #-------------------------------------------------- echo "Connector Configuration" #-------------------------------------------------- port 1/1/c1 description "To_Nokia_PE1" connector breakout c1-10g exit no shutdown exit port 1/1/c2 description "To_Cisco_P3" connector breakout c1-10g exit no shutdown exit #-------------------------------------------------- echo "Port Configuration" #-------------------------------------------------- port 1/1/c1/1 description "To_Nokia_PE1" ethernet exit no shutdown exit port 1/1/c2/1 description "To_Cisco_P3" ethernet exit no shutdown exit #-------------------------------------------------- echo "Router (Network Side) Configuration" #-------------------------------------------------- router Base interface "system" address 10.10.10.2/32 no shutdown exit interface "to_P3" address 192.168.23.2/24 port 1/1/c2/1 no shutdown exit interface "to_PE1" address 192.168.12.2/24 port 1/1/c1/1 no shutdown exit autonomous-system 65000 router-id 10.10.10.2 #-------------------------------------------------- echo "OSPFv2 Configuration" #-------------------------------------------------- ospf 0 area 0.0.0.0 interface "system" no shutdown exit interface "to_P3" interface-type point-to-point mtu 1500 authentication-type password authentication-key abc1234 no shutdown exit exit no shutdown exit #-------------------------------------------------- echo "ISIS Configuration" #-------------------------------------------------- isis 0 level-capability level-2 area-id 49.0200 interface "system" level-capability level-2 passive no shutdown exit interface "to_PE1" level-capability level-2 interface-type point-to-point no shutdown exit no shutdown exit #-------------------------------------------------- echo "LDP Configuration" #-------------------------------------------------- ldp import-pmsi-routes exit interface-parameters interface "to_P3" dual-stack ipv4 no shutdown exit no shutdown exit interface "to_PE1" dual-stack ipv4 no shutdown exit no shutdown exit exit targeted-session exit no shutdown exit exit #-------------------------------------------------- echo "Policy Configuration" #-------------------------------------------------- policy-options begin prefix-list "Loopback" prefix 10.10.10.0/24 prefix-length-range 32-32 exit policy-statement "BGP-LU-EXPORT" entry 10 from prefix-list "Loopback" exit action accept exit exit exit commit exit #-------------------------------------------------- echo "BGP Configuration" #-------------------------------------------------- bgp group "Internal" family label-ipv4 next-hop-self cluster 10.10.10.2 export "BGP-LU-EXPORT" peer-as 65000 neighbor 10.10.10.1 exit neighbor 10.10.10.3 exit exit no shutdown exit exit exit all
P3#show running-config ! mpls label protocol ldp ! mpls ldp explicit-null ! interface Loopback0 ip address 10.10.10.3 255.255.255.255 ip ospf 1 area 0 ! interface GigabitEthernet1 description "To_P3" ip address 192.168.34.3 255.255.255.0 ip router isis negotiation auto mpls ip mpls label protocol ldp mpls ldp discovery transport-address 10.10.10.3 isis circuit-type level-1 isis network point-to-point ! interface GigabitEthernet2 description "To_Nokia_P2" ip address 192.168.23.3 255.255.255.0 ip ospf authentication-key abc1234 ip ospf network point-to-point ip ospf 1 area 0 negotiation auto mpls ip mpls label protocol ldp mpls ldp discovery transport-address 10.10.10.3 ! router ospf 1 area 0 authentication passive-interface Loopback0 ! router isis net 49.0100.0100.1001.0003.00 is-type level-1 redistribute connected level-1 ! router bgp 65000 bgp router-id 10.10.10.3 bgp log-neighbor-changes neighbor 10.10.10.2 remote-as 65000 neighbor 10.10.10.2 update-source Loopback0 neighbor 10.10.10.4 remote-as 65000 neighbor 10.10.10.4 update-source Loopback0 ! address-family ipv4 redistribute connected route-map BGP-LU-EXPORT neighbor 10.10.10.2 activate neighbor 10.10.10.2 send-community neighbor 10.10.10.2 route-reflector-client neighbor 10.10.10.2 next-hop-self all neighbor 10.10.10.2 send-label neighbor 10.10.10.4 activate neighbor 10.10.10.4 send-community neighbor 10.10.10.4 route-reflector-client neighbor 10.10.10.4 next-hop-self all neighbor 10.10.10.4 send-label exit-address-family ! route-map BGP-LU-EXPORT permit 10 match interface Loopback0 ! mpls ldp router-id Loopback0 force ! end
PE4#show running-config ! mpls label protocol ldp ! mpls ldp explicit-null ! interface Loopback0 ip address 10.10.10.4 255.255.255.255 ip router isis isis circuit-type level-1 ! interface GigabitEthernet1 description "To_P3" ip address 192.168.34.4 255.255.255.0 ip router isis negotiation auto mpls ip mpls label protocol ldp mpls ldp discovery transport-address 10.10.10.4 isis circuit-type level-1 isis network point-to-point ! router isis net 49.0100.0100.1001.0004.00 is-type level-1 ! router bgp 65000 bgp router-id 10.10.10.4 bgp log-neighbor-changes neighbor 10.10.10.3 remote-as 65000 neighbor 10.10.10.3 update-source Loopback0 ! address-family ipv4 redistribute connected route-map BGP-LU-EXPORT neighbor 10.10.10.3 activate neighbor 10.10.10.3 send-community neighbor 10.10.10.3 send-label exit-address-family ! route-map BGP-LU-EXPORT permit 10 match interface Loopback0 ! mpls ldp router-id Loopback0 force ! end
Show Router Status
A:PE1# show router route-table =============================================================================== Route Table (Router: Base) =============================================================================== Dest Prefix[Flags] Type Proto Age Pref Next Hop[Interface Name] Metric ------------------------------------------------------------------------------- 10.10.10.1/32 Local Local 17h23m33s 0 system 0 10.10.10.2/32 Remote ISIS 17h22m50s 18 192.168.12.2 10 10.10.10.3/32 Remote BGP_LABEL 02h11m42s 170 10.10.10.2 (tunneled) 10 10.10.10.4/32 Remote BGP_LABEL 02h11m42s 170 10.10.10.2 (tunneled) 10 192.168.12.0/24 Local Local 17h23m23s 0 to_P2 0 ------------------------------------------------------------------------------- No. of Routes: 5 Flags: n = Number of times nexthop is repeated B = BGP backup route available L = LFA nexthop available S = Sticky ECMP requested =============================================================================== A:PE1# A:PE1# show router ldp bindings ipv4 #--- snip some output ---- =============================================================================== Prefix Peer FEC-Flags IgrLbl EgrLbl EgrNextHop EgrIntf/LspId ------------------------------------------------------------------------------- 10.10.10.2/32 10.10.10.2:0 -- 524287 192.168.12.2 1/1/c1/1 =============================================================================== A:PE1# A:PE1# show router bgp routes label-ipv4 =============================================================================== BGP Router ID:10.10.10.1 AS:65000 Local AS:65000 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete =============================================================================== BGP Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id IGP Cost As-Path Label ------------------------------------------------------------------------------- *i 10.10.10.1/32 100 10 10.10.10.2 None 10 No As-Path 524278 *i 10.10.10.2/32 100 None 10.10.10.2 None 10 No As-Path 524281 u*>i 10.10.10.3/32 100 11 10.10.10.2 None 10 No As-Path 524279 u*>? 10.10.10.4/32 100 0 10.10.10.2 None 10 No As-Path 524280 ------------------------------------------------------------------------------- Routes : 4 ===============================================================================
A:P2# show router route-table =============================================================================== Route Table (Router: Base) =============================================================================== Dest Prefix[Flags] Type Proto Age Pref Next Hop[Interface Name] Metric ------------------------------------------------------------------------------- 10.10.10.1/32 Remote ISIS 23h06m03s 18 192.168.12.1 10 10.10.10.2/32 Local Local 23h06m28s 0 system 0 10.10.10.3/32 Remote OSPF 23h06m10s 10 192.168.23.3 11 10.10.10.4/32 Remote BGP_LABEL 23h06m04s 170 10.10.10.3 (tunneled) 11 192.168.12.0/24 Local Local 23h06m18s 0 to_PE1 0 192.168.23.0/24 Local Local 23h06m18s 0 to_P3 0 ------------------------------------------------------------------------------- No. of Routes: 6 Flags: n = Number of times nexthop is repeated B = BGP backup route available L = LFA nexthop available S = Sticky ECMP requested A:P2# A:P2# show router ldp bindings ipv4 #--- snip some output ---- =============================================================================== Prefix Peer FEC-Flags IgrLbl EgrLbl EgrNextHop EgrIntf/LspId ------------------------------------------------------------------------------- 10.10.10.1/32 10.10.10.1:0 -- 524287 192.168.12.1 1/1/c1/1 10.10.10.3/32 10.10.10.3:0 -- 0 192.168.23.3 1/1/c2/1 =============================================================================== A:P2# A:P2# show router bgp routes label-ipv4 =============================================================================== BGP Router ID:10.10.10.2 AS:65000 Local AS:65000 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete =============================================================================== BGP Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id IGP Cost As-Path Label ------------------------------------------------------------------------------- *i 10.10.10.1/32 100 None 10.10.10.1 None 10 No As-Path 524279 *? 10.10.10.3/32 100 0 10.10.10.3 None 11 No As-Path 3 u*>? 10.10.10.4/32 100 0 10.10.10.3 None 11 No As-Path 16 ------------------------------------------------------------------------------- Routes : 3 ===============================================================================
P3#show ip route Gateway of last resort is not set 10.0.0.0/32 is subnetted, 4 subnets B 10.10.10.1 [200/10] via 10.10.10.2, 08:11:41 O 10.10.10.2 [110/1] via 192.168.23.2, 23:22:59, GigabitEthernet2 C 10.10.10.3 is directly connected, Loopback0 i L1 10.10.10.4 [115/20] via 192.168.34.4, 2d06h, GigabitEthernet1 192.168.23.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.23.0/24 is directly connected, GigabitEthernet2 L 192.168.23.3/32 is directly connected, GigabitEthernet2 192.168.34.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.34.0/24 is directly connected, GigabitEthernet1 L 192.168.34.3/32 is directly connected, GigabitEthernet1 P3# P3#show mpls forwarding-table Local Outgoing Prefix Bytes Label Outgoing Next Hop Label Label or Tunnel Id Switched interface 16 explicit-n 10.10.10.4/32 4631745 Gi1 192.168.34.4 18 524278 10.10.10.1/32 1088878 Gi2 192.168.23.2 19 524287 10.10.10.2/32 0 Gi2 192.168.23.2 P3# P3#show ip bgp ipv4 unicast labels Network Next Hop In label/Out label 10.10.10.1/32 10.10.10.2 18/524278 10.10.10.2/32 10.10.10.2 19/524281 10.10.10.3/32 10.10.10.2 imp-null/524279 0.0.0.0 imp-null/nolabel 10.10.10.4/32 10.10.10.4 16/imp-null P3#
PE4#show ip route Gateway of last resort is not set 10.0.0.0/32 is subnetted, 4 subnets B 10.10.10.1 [200/10] via 10.10.10.3, 08:17:51 B 10.10.10.2 [200/0] via 10.10.10.3, 23:28:31 i L1 10.10.10.3 [115/10] via 192.168.34.3, 2d06h, GigabitEthernet1 C 10.10.10.4 is directly connected, Loopback0 i L1 192.168.23.0/24 [115/10] via 192.168.34.3, 2d06h, GigabitEthernet1 192.168.34.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.34.0/24 is directly connected, GigabitEthernet1 L 192.168.34.4/32 is directly connected, GigabitEthernet1 PE4# PE4#show mpls forwarding-table Local Outgoing Prefix Bytes Label Outgoing Next Hop Label Label or Tunnel Id Switched interface 16 No Label l2ckt(1) 75322 Gi2 point2point 17 explicit-n 192.168.23.0/24 0 Gi1 192.168.34.3 18 No Label 192.168.104.0/24[V] \ 3306 aggregate/COTTON 19 explicit-n 10.10.10.3/32 0 Gi1 192.168.34.3 PE4# PE4#show ip bgp ipv4 unicast labels Network Next Hop In label/Out label 10.10.10.1/32 10.10.10.3 nolabel/18 10.10.10.2/32 10.10.10.3 nolabel/19 10.10.10.3/32 10.10.10.3 nolabel/imp-null 10.10.10.4/32 0.0.0.0 imp-null/nolabel PE4#
MPLS L2VPN Configuration
A:PE1# admin display-config #-------------------------------------------------- echo "Port Configuration" #-------------------------------------------------- port 1/1/c2 description "To_Cisco_CE5_fa0/0_L2VPN" connector breakout c1-10g exit no shutdown exit port 1/1/c2/1 description "To_Cisco_CE5_fa0/0_L2VPN" ethernet mode access exit no shutdown exit #-------------------------------------------------- echo "LDP Configuration" #-------------------------------------------------- router ldp targeted-session peer 10.10.10.4 no shutdown exit exit no shutdown exit exit #-------------------------------------------------- echo "Service Configuration" #-------------------------------------------------- service sdp 14 mpls create far-end 10.10.10.4 bgp-tunnel keep-alive shutdown exit no shutdown exit epipe 1001 name "L2VPN" customer 1 create description "L2VPN" sap 1/1/c2/1 create description "To_Cisco_CE5_fa0/0_L2VPN" no shutdown exit spoke-sdp 14:1001 create description "To_Cisco_PE4_xconnect" no shutdown exit no shutdown exit A:PE1# #=========== Show MPLS L2VPN Status ============== A:PE1# show router ldp session ============================================================================== LDP IPv4 Sessions ============================================================================== Peer LDP Id Adj Type State Msg Sent Msg Recv Up Time ------------------------------------------------------------------------------ 10.10.10.2:0 Link Established 3368 3371 0d 02:29:36 10.10.10.4:0 Targeted Established 1673 1811 0d 02:29:25 ------------------------------------------------------------------------------ No. of IPv4 Sessions: 2 ============================================================================== A:PE1# show service sdp-using =============================================================================== SDP Using =============================================================================== SvcId SdpId Type Far End Opr I.Label E.Label State ------------------------------------------------------------------------------- 1001 14:1001 Spok 10.10.10.4 Up 524283 16 ------------------------------------------------------------------------------- Number of SDPs : 1 ------------------------------------------------------------------------------- =============================================================================== A:PE1#
PE4#show running-config ! mpls ldp neighbor 10.10.10.1 targeted ldp ! pseudowire-class MPLS encapsulation mpls ! interface GigabitEthernet2 description To_Cisco_CE6 no ip address xconnect 10.10.10.1 1001 encapsulation mpls pw-class MPLS ! PE4# #=========== Show MPLS L2VPN Status ============== PE4#show mpls ldp neighbor brief Peer LDP id Uptime NSR GR Discovery Address Labels ----------- ------ --- -- --------- ------- ------ 10.10.10.3:0 2d06h N N 1 3 11 10.10.10.1:0 08:18:41 N N 1 2 0 PE4# PE4#show mpls l2transport binding Destination Address: 10.10.10.1,VC ID: 1001 Local Label: 16 Cbit: 0, VC Type: Ethernet, GroupID: n/a MTU: 1500, Interface Desc: To_vMX_CE6 VCCV: CC Type: CW [1], RA [2], TTL [3] CV Type: LSPV [2] Remote Label: 524283 Cbit: 0, VC Type: Ethernet, GroupID: 0 MTU: 1500, Interface Desc: n/a VCCV: CC Type: RA [2] CV Type: LSPV [2], BFD/UDP [3] PE4#
CE5#show running-config ! interface FastEthernet0/0 description To_NOKIA_PE1_1/1/2_L2 ip address 192.168.56.5 255.255.255.0 ! CE6#show running-config ! interface FastEthernet0/0 description To_Cisco_PE4_Gi2_L2 ip address 192.168.56.6 255.255.255.0 ! #=========== Ping Test CE5 to CE6 ============== CE5#ping 192.168.56.6 source 192.168.56.5 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.56.6, timeout is 2 seconds: Packet sent with a source address of 192.168.56.5 !!!!! CE5#
MPLS L3VPN Configuration
A:PE1# admin display-config configure #-------------------------------------------------- echo "Port Configuration" #-------------------------------------------------- port 1/1/c3 description "To_Cisco_CE5_fa0/1_L3VPN" connector breakout c1-10g exit no shutdown exit port 1/1/c3/1 description "To_Cisco_CE5_fa0/1_L3VPN" ethernet mode access exit no shutdown exit #-------------------------------------------------- echo "Service Configuration" #-------------------------------------------------- service vprn 100 name "COTTON" customer 1 create route-distinguisher 65000:100 auto-bind-tunnel resolution any exit vrf-target target:65000:100 interface "to_CE5_l3" create address 192.168.101.1/24 sap 1/1/c3/1 create exit exit no shutdown exit exit #-------------------------------------------------- echo "BGP Configuration" #-------------------------------------------------- bgp group "Seamless" family vpn-ipv4 peer-as 65000 neighbor 10.10.10.4 exit exit no shutdown exit exit A:PE1# #=========== Show Status MPLS L3VPN ============== A:PE1# show router 100 route-table =============================================================================== Route Table (Service: 100) =============================================================================== Dest Prefix[Flags] Type Proto Age Pref Next Hop[Interface Name] Metric ------------------------------------------------------------------------------- 192.168.101.0/24 Local Local 23h01m27s 0 to_CE5_l3 0 192.168.104.0/24 Remote BGP VPN 07h49m42s 170 10.10.10.4 (tunneled:BGP) 1000 ------------------------------------------------------------------------------- No. of Routes: 2 Flags: n = Number of times nexthop is repeated B = BGP backup route available L = LFA nexthop available S = Sticky ECMP requested =============================================================================== A:PE1# A:PE1# show router bgp routes vpn-ipv4 =============================================================================== BGP Router ID:10.10.10.1 AS:65000 Local AS:65000 =============================================================================== Legend - Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid l - leaked, x - stale, > - best, b - backup, p - purge Origin codes : i - IGP, e - EGP, ? - incomplete =============================================================================== BGP VPN-IPv4 Routes =============================================================================== Flag Network LocalPref MED Nexthop (Router) Path-Id IGP Cost As-Path Label ------------------------------------------------------------------------------- u*>? 65000:100:192.168.104.0/24 100 0 10.10.10.4 None 0 No As-Path 18 ------------------------------------------------------------------------------- Routes : 1 =============================================================================== A:PE1#
PE4#show running-config ! ip vrf COTTON rd 65000:100 route-target export 65000:100 route-target import 65000:100 ! interface GigabitEthernet3 ip vrf forwarding COTTON ip address 192.168.104.1 255.255.255.0 ! router bgp 65000 bgp router-id 10.10.10.4 neighbor 10.10.10.1 remote-as 65000 neighbor 10.10.10.1 update-source Loopback0 ! address-family vpnv4 neighbor 10.10.10.1 activate neighbor 10.10.10.1 send-community extended exit-address-family ! address-family ipv4 vrf COTTON redistribute connected exit-address-family ! PE4# #=========== Show Status MPLS L3VPN ============== PE4#show ip route vrf COTTON Routing Table: COTTON Gateway of last resort is not set B 192.168.101.0/24 [200/0] via 10.10.10.1, 08:20:22 192.168.104.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.104.0/24 is directly connected, GigabitEthernet3 L 192.168.104.1/32 is directly connected, GigabitEthernet3 PE4# PE4#show ip bgp vpnv4 vrf COTTON labels Network Next Hop In label/Out label Route Distinguisher: 65000:100 (COTTON) 192.168.101.0 10.10.10.1 nolabel/524286 192.168.104.0 0.0.0.0 18/nolabel(COTTON) PE4#
CE5#show running-config ! interface FastEthernet0/1 description To_NOKIA_PE1_1/1/3_L3 ip address 192.168.101.5 255.255.255.0 duplex auto speed auto ! ip route 192.168.104.0 255.255.255.0 192.168.101.1 ! CE5# CE6#show running-config ! interface FastEthernet0/1 description To_Cisco_PE4_Gi3_L3 ip address 192.168.104.6 255.255.255.0 duplex auto speed auto ! ip route 192.168.101.0 255.255.255.0 192.168.104.1 ! #==== Ping Test CE6 to CE5 =========== CE6#ping 192.168.56.5 source 192.168.56.6 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.56.5, timeout is 2 seconds: Packet sent with a source address of 192.168.56.6 !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 16/21/32 ms CE6#