C3850 IP interface not reachable

[gaigl]

Hello,

one of our C3850 makes problems:

switching is ok, but the management Interface:

"interface Vlan252
ip address 172.27.252.141 255.255.252.0"

is not reachable.

I'm connected on the console and the IP stack is up (can ping myself), routing ok:

C 172.27.252.0/22 is directly connected, Vlan252
L 172.27.252.141/32 is directly connected, Vlan252

switch#show arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 172.27.252.141 - 2c3e.cf23.78db ARPA Vlan252
Internet 172.27.253.181 0 Incomplete ARPA

trunks are up and running, vtp is ok, but but the interf vlan ip can't get connection to other IP's, so the switch is working but not manageable.

Any Ideas?

usually I would do a reload, but the connected systems are too important,

Karl

[M02@rt37]

Hello @gaigl,

what about your routing table?

Please share the output here. 

[gaigl]

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
+ - replicated route, % - next hop override

Gateway of last resort is not set

172.27.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.27.252.0/22 is directly connected, Vlan252
L 172.27.252.141/32 is directly connected, Vlan252

that's ok, this the route for our Management-Network, it's the same on other switches

[MHM Cisco World]

Internet 172.27.252.141 - 2c3e.cf23.78db ARPA Vlan252
Internet 172.27.253.181 0 Incomplete ARPA

Two different subnet

You need to config

İp defualt gateway in SW point to vlan svi of sw or router that have inter-vlan enable 

[gaigl]

no, not different Subnets: mask is 255.255.252.0

and this a not-routed dedicated Management-VLAN

[MHM Cisco World]

255.255.252.0 <<- this cover both subnet 
arp incomplete<<- this meaning that there is issue in  subnet mask, make double check in subnet mask of 172.27.253.181 vlan SVI

[gaigl]

thanks for answer, but 172.27.253.181 is logging or ntp server, working fine for other switches,

the uncomplete arp-entry is generated for every IP im pinging or about a syslog, ntp, whatever the switch is trying

[MHM Cisco World]

SW1 with issue 
SW2 transit SW 
SW3/R is inter VLAN 

SW1(VLAN252)-SW2-SW3/R(VLAN252)
SW1(VALN252) send ARP the arp will follow l2 from SW1 to SW2 to SW3 
make double check the SW1 VLAN 252 subnetmask 
make double check the VLAN 252 allow in all path to SW3/R 
make double check the VLAN 252 in SW3/R have correct subnet mask

[gaigl]

I've checked this all on Core and Distribution with "show interf trunk", everything is fine, 

checked Interface VLAN 252 on Core -> otherwise our other 50 Switches wouldn't work

Info: we had maintanance downtime of network (replacing core) but this switch is connected to distribution layer (Nexus), and all other switch had no problem.

So I think, there's no other solution than reload  

[MHM Cisco World]

distribute layer is NSK, does NSK have SVI for VLAN5252 ? If yes 
then ping to SVI of NSK 

[gaigl]

already tried, no success

[gaigl]

the SVI is some kind of "locked in", no communication to other devices, but Layer 2 is working

[MHM Cisco World]

ping SVI NSK source VLAN252 <<- try this 

[gaigl]

Sending 5, 100-byte ICMP Echos to 172.27.252.151, timeout is 2 seconds:

Packet sent with a source address of 172.27.252.141
.....
Success rate is 0 percent (0/5)

[MHM Cisco World]

Can I see 

Show interface trunk