Task TS01: H11(172.16.101.10) cannot ping H21(172.16.101.11)

_images/ts01_topology.png

Note

To get started, please select in lab manager option 04 to initialize lab devices. Please wait a minute after lab start for network convergence.

H11 node

 1ts01-H11#ping 172.16.101.11
 2Type escape sequence to abort.
 3Sending 5, 100-byte ICMP Echos to 172.16.101.11, timeout is 2 seconds:
 4.....
 5Success rate is 0 percent (0/5)
 6
 7ts01-H11#show ip arp
 8Protocol  Address          Age (min)  Hardware Addr   Type   Interface
 9Internet  172.16.101.1            3   aabb.cc80.0300  ARPA   Ethernet0/0
10Internet  172.16.101.10           -   0000.0001.0101  ARPA   Ethernet0/0
11Internet  172.16.101.11           0   Incomplete      ARPA

We will start with the leaf to which the host is connected – Leaf1. In the host information we saw that ARP is incomplete. Lets check the same on Leaf1 and also look into the NVE peering.

Note

Note that VRF “green” is used on the Leaf1 node for L3VNI.

L1 node

1ts01-L1#show ip arp vrf green
2Protocol  Address          Age (min)  Hardware Addr   Type   Interface
3Internet  10.1.254.3              -   aabb.cc80.0300  ARPA   Vlan901
4Internet  172.16.101.1            -   aabb.cc80.0300  ARPA   Vlan101
5Internet  172.16.101.10           1   0000.0001.0101  ARPA   Vlan101
6Internet  172.16.102.10           2   0000.0001.0102  ARPA   Vlan102

We won’t see ARPs for clients over remote VTEP

 1ts01-L1#show nve peers
 2'M' - MAC entry download flag  'A' - Adjacency download flag
 3'4' - IPv4 flag  '6' - IPv6 flag
 4
 5Interface  VNI      Type Peer-IP          RMAC/Num_RTs   eVNI     state flags UP time
 6nve1       50901    L3CP 10.1.254.4       aabb.cc80.0400 50901      UP  A/M/4 00:03:48
 7nve1       50901    L3CP 10.1.254.5       aabb.cc80.0500 50901      UP  A/M/4 00:03:48
 8nve1       10102    L2CP 10.1.254.4       4              10102      UP   N/A  00:03:48
 9nve1       10102    L2CP 10.1.254.5       4              10102      UP   N/A  00:03:48
10nve1       10102    L2CP 10.1.254.6       2              10102      UP   N/A  00:03:48
11nve1       10102    L2CP 10.1.254.7       2              10102      UP   N/A  00:03:48

In the NVE peers table above that there are no entries that would be showing a peering over VNI 10101. Therefore, lets check the EVI for the vlan where we have H11 attached – vlan 101.

The EVI outputs show the vlan 101 is mapped to the L2 VNI 10110 but the VTEP IP is UNKNOWN.

 1ts01-L1#show l2vpn evpn evi vlan 101
 2EVI   VLAN  Ether Tag  L2 VNI    Multicast     Pseudoport
 3----- ----- ---------- --------- ------------- ------------------
 4101   101   0          10110     UNKNOWN       Et0/0:101
 5                                               Et1/1:101
 6
 7ts01-L1#show l2vpn evpn evi vlan 101 detail
 8EVPN instance:       101 (VLAN Based)
 9RD:                10.1.255.3:101 (auto)
10Import-RTs:        65001:101
11Export-RTs:        65001:101
12Per-EVI Label:     none
13State:             Established
14Replication Type:  Ingress (global)
15Encapsulation:     vxlan
16IP Local Learn:    Enabled (global)
17Adv. Def. Gateway: Enabled (global)
18Re-originate RT5:  Disabled
19Adv. Multicast:    Disabled (global)
20Vlan:              101
21    Ethernet-Tag:    0
22    State:           Established
23    Flood Suppress:  Attached
24    Core If:
25    Access If:
26    NVE If:
27    RMAC:            0000.0000.0000
28    Core Vlan:       0
29    L2 VNI:          10110
30    L3 VNI:          0
31    VTEP IP:         UNKNOWN
32    Pseudoports:
33    Ethernet0/0 service instance 101
34        Routes: 1 MAC, 1 MAC/IP
35    Peers:
36    10.1.254.4
37        Routes: 2 MAC, 2 MAC/IP, 1 IMET, 0 EAD
38    10.1.254.5
39        Routes: 2 MAC, 2 MAC/IP, 1 IMET, 0 EAD
40    10.1.254.6
41        Routes: 1 MAC, 1 MAC/IP, 1 IMET, 0 EAD
42    10.1.254.7
43        Routes: 1 MAC, 2 MAC/IP, 1 IMET, 0 EAD

The MAC/IP information from BGP routes shows that the next show information is actually expecting 10101.

 1ts01-L1#show l2route evpn mac ip
 2EVI       ETag  Prod    Mac Address         Host IP                Next Hop(s)
 3----- ---------- ----- -------------- --------------- --------------------------
 4101          0 L2VPN 0000.0001.0101   172.16.101.10                  Et0/0:101
 5101          0   BGP 0000.0002.0101   172.16.101.11         V:10101 10.1.254.4
 6101          0   BGP 0000.0003.0101   172.16.101.12         V:10101 10.1.254.5
 7101          0   BGP aabb.cc80.0400    172.16.101.1         V:10101 10.1.254.4
 8101          0   BGP aabb.cc80.0500    172.16.101.1         V:10101 10.1.254.5
 9101          0   BGP aabb.cc80.0600    172.16.101.1         V:10101 10.1.254.6
10101          0   BGP aabb.cc80.0700    172.16.101.1         V:10101 10.1.254.7
11<...skip...>

Do those 2 VNIs exist on the switch? Looks like 10110 does not exist – in the configuration of NVE we can find out which VNI is actually expected to be here.

 1ts01-L1#show nve vni 10101
 2Interface  VNI        Multicast-group VNI state  Mode  VLAN  cfg vrf
 3nve1       10101      N/A             BD Down/Re L2CP  N/A   CLI N/A
 4
 5ts01-L1#show nve vni 10110
 6Interface  VNI        Multicast-group VNI state  Mode  VLAN  cfg vrf
 7% VNI 10110 doesnt exist
 8
 9ts01-L1#show run int nve1
10interface nve1
11 no ip address
12 source-interface Loopback1
13 host-reachability protocol bgp
14 member vni 10101 ingress-replication
15 member vni 10102 mcast-group 225.0.1.102
16 member vni 50901 vrf green
17 end
18
19ts01-L1#show run vlan 101
20vlan configuration 101
21 member evpn-instance 101 vni 10110

We have identified that there is a mismatch in vlan-to-VNI mapping, as for vlan 101 L2VNI 10110 is used instead of the expected VNI 10101. Correct L2VNI is not configured on the switch.

Lets fix the configuration mistake on L1 node and reconfigure the NVE-VNI membership to retrigger the NVE peer learning for VNI 10101.

L1 node

1conf t
2no vlan configuration 101
3vlan configuration 101
4 member evpn-instance 101 vni 10101
5!
6int nve1
7 no member vni 10101 ingress-replication
8 member vni 10101 ingress-replication

Checking the NVE peers for that VNI afterwards, we see remote Leafs and connectivity start working.

L1 node

1ts01-L1#show nve peers vni 10101
2'M' - MAC entry download flag  'A' - Adjacency download flag
3'4' - IPv4 flag  '6' - IPv6 flag
4
5Interface  VNI      Type Peer-IP          RMAC/Num_RTs   eVNI     state flags UP time
6nve1       10101    L2CP 10.1.254.4       5              10101      UP   N/A  00:00:23
7nve1       10101    L2CP 10.1.254.5       5              10101      UP   N/A  00:00:23
8nve1       10101    L2CP 10.1.254.6       3              10101      UP   N/A  00:00:23
9nve1       10101    L2CP 10.1.254.7       3              10101      UP   N/A  00:00:23

H11 node

1ts01-H11#ping 172.16.101.11
2Type escape sequence to abort.
3Sending 5, 100-byte ICMP Echos to 172.16.101.11, timeout is 2 seconds:
4.!!!!
5Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/1 ms