06-06-2024 06:55 AM
Good afternoon,
I have a question that is driving me crazy trying to understand.
In a 2960 switch, I have the following configuration:
VLAN 100 - IP 10.0.100.1 (mngmt vlan)
VLAN 1 - no ip address
Default gateway - 192.168.1.1 (VLAN1)
And it works fine.
In a 9200 switch with the same configuration, it doesn't work unless I give an ip to VLAN 1
Ex:
VLAN 100 - IP 10.0.100.2 (mngmt vlan)
VLAN 1 - ip 192.168.1.10 (if I clear the IP from the VLAN as in the previous example, the switch doesn't communicate with the network)
Default gateway - 192.168.1.1 (VLAN1)
This is driving me crazy cause i would like to understaind the logic (the 9200 is used as L2 SW)
TY in advanced
06-06-2024 07:02 AM
can you confirm if you use ip routing in both SW
can you share show ip route for both SW
MHM
06-06-2024 07:18 AM - edited 06-06-2024 07:18 AM
rigth now on the 9200 i have the gtw on the same vlan as the mngmt so i can access the sw
but it was something like this on the 9200
Gateway of last resort is 192.168.1.1 to network 0.0.0.0
S* 0.0.0.0/0 [0/0] via 192.168.1.1
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.0.100.0/24 is directly connected, Vlan100
L 10.0.100.10/32 is directly connected, Vlan100
06-06-2024 07:12 AM
Hi,
In order for the default gateway to work correctly, you need to have an SVI with an IP in the same subnet as 192.168.1.1 (VLAN1) on that switch. So, the config on the 9200 is correct.
HTH
06-06-2024 07:16 AM
this is the part I understand, what I don't understand is why on the 2960 I can have a management IP from one VLAN and a gateway IP from another VLAN without any problem
06-06-2024 07:20 AM
In 2960 you either run ip routing and SW use routing not default GW or your mgmt pc connect to vlan 100 and hence no need routing
Without see what I ask above I can not know what issue here
MHM
06-06-2024 07:23 AM
The 2960 doesn't have ip routing as it is a L2 SW
06-06-2024 07:24 AM
I don't understand is why on the 2960 I can have a management IP from one VLAN and a gateway IP from another VLAN without any problem
Can't be, unless you are not using the default-gateway.
Can you post the output of "sh run" from the 2960?
BTW, since the 2960 is purely a layer-2 switch, you can only have one IP with one SVI on it and that is used for management.
HTH
06-06-2024 07:28 AM
interface Vlan1
no ip address
no ip route-cache
!
interface Vlan100
ip address 10.0.100.121 255.255.255.0
no ip route-cache
!
interface Vlan998
no ip address
no ip route-cache
!
ip default-gateway 192.168.1.1
ip http server
ip http authentication local
ip http secure-server
and works fine, this is turn me mad not because i don't know how to make it work on the 9200 but because i don't understaind the logic
06-06-2024 07:31 AM
For 2960
Your mgmt PC which IP use ?
In which port it connect, port with vlan1 or vlan 100?
MHM
06-06-2024 07:40 AM
i Use the VLAN 100 ip, the uplink is connected on port gi0/4 (trunk with all vlans, the port in the core is with the same conf)
interface GigabitEthernet0/4
description ==UPLINK CORE==
switchport mode trunk
06-06-2024 07:43 AM
So no need defualt GW as I mention before
The traffic is bridge not routing
MHM
06-06-2024 08:02 AM
Ok, guess i found my answer, on C2960 by default ip proxy-arp is active, but not in the C9200, gone make some tests to see if this theory is correct
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