06-27-2023 12:25 AM
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
Solved! Go to Solution.
07-06-2023 05:33 AM
I think no need continue search:
cpu is constant on 100%, now I'm getting maintanance, and installing new IOS-XE
06-27-2023 12:36 AM
Hello @gaigl,
what about your routing table?
Please share the output here.
06-27-2023 01:17 AM
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
06-27-2023 02:07 AM
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
06-27-2023 02:28 AM
no, not different Subnets: mask is 255.255.252.0
and this a not-routed dedicated Management-VLAN
06-27-2023 02:38 AM
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
06-27-2023 02:44 AM
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
06-27-2023 03:01 AM
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
06-27-2023 03:15 AM
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
06-27-2023 03:18 AM
distribute layer is NSK, does NSK have SVI for VLAN5252 ? If yes
then ping to SVI of NSK
06-27-2023 03:57 AM
already tried, no success
06-27-2023 03:59 AM
the SVI is some kind of "locked in", no communication to other devices, but Layer 2 is working
06-27-2023 04:10 AM
ping SVI NSK source VLAN252 <<- try this
06-27-2023 05:14 AM
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)
06-27-2023 06:06 AM
Can I see
Show interface trunk
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