I have some question about SVI (switch virtual interface)
Q: I have switch 2960 with VLAN 20 & VLAN 50
VLAN 10 : ip address 192.168.10.X
VLAN 20 ip address 192.168.20.X
With no default gateway I am able to access the my server which is on different VLAN
Can some explain how is working without default gateway my studies you can ping between same VLAN without switch default-gateway but if any thing going to the different VLAN then they need a default-gateway to route right I am confuse
If you have more than one SVI active then you have a L3 switch.
So inter vlan routing will automatically route between the SVI for vlan A and the SVI for vlan B.
I never realised 2960 supported L3 switch. Are you sure you have not got a router on a stick hiding somewhere.
Proxy arp on the router monitors traffic and if it sees a requested for a route it knows about it replies with his arp and the routes the traffic.
To fully answer your question, (accurately), it would be helpful to know:
VLANs on the switch (exactly)
VLAN interfaces on the switch, including IP address
Which port the server is connected to, and what VLAN is that port assigned
What the IP address of the server is
With that info, there is a better chance of getting a meaningful answer, that is also correct.
Let us know.
2960 is a L2 switch.
Thanks for your Help
What happen I have a 3750 switch swith Multiple SVI on it
VL:21 ----> Accounting Users
VL:31 ----> IT users
VL:22 ----> Sales Users
VL:10 ----> Switch Management VLAN
and the defaylt-gateway on the switch is 192.168.10.X
and I have 48 ports distributed in VL:21 , VL:31 & VL:22 and the issues form the switch if I am trying to ping the VL:11 which is monitoring VLAN and I am geeting timeout form my 3750 switch I dont know why but I am doing ping between three VL: 21,22,23 thats fine and when I shudwon the 21,22,31 SVI and then I am able to ping from the 3750 switch to VLAN 111 I have not idea why
all the vlans are alreayd allowed on the trunk
This 3750 connected to the core and the core is doing the routing
can anyone clarify the why is like this
If you have a 3750 without ip routing then it is a L2 switch
ip default-gateway simply allows you to telnet to the management vlan
If you have a 3750 with ip routing then it is a L3 switch. default-gateway is ignored. Use ip route 0.0.0.0 0.0.0.0 a.b.c.d or ip default-network or routing protocol. Inter-vlan routing will occur naturally as well as inter routed port.
Thanks for your reply
Yes your are right 2960 is just layer 2 switch but why we define multipe SVI on layer switch as we know is not gona perfrom routing and how the traffic from VLAN A to VLAB will go I think throught the default gate way correct
but in my case the 2960 has two vlan 110,100 and SVI are up and the server on 110 VLAN is able to ping across the network and switch and switch have no default-gateway define I have ni idea how they are communicating
Please help me out
Please see the attchment for 2960 switch this switch have no default-gateway define and servers connected to that switch si fine they can communicate accross the network I have no idea how
Please see attchment
2960 do support multiple SVI since 12.2 (something) but not routing. I think traffic is going down gi0/1 and the core is using proxy arp to do the routing for you.
Thanks for your help I will appreciate that
if you don't mind I have qucik question that let say SVI just for to access the swicth from different VLAN right if I shutdown all the SVI and If I don't define default gateway how gona traffic will travel to different VLAN or diffent switch my asnwer I will get time out because switch dont know how to take the traffic right so It means the default-gateway is used to carry traffic to different vlan or different switch right if this right then why in some forum says default gateway is used for switch remote management please advise
onece again thanks very much for yout time
For a L2 switch such as the 2960 the int vlan x is used for switch management via telnet.
default-gateway is used to allow the switch management output to get back to the person doing the telnet.
It is nothing to do with inter-vlan routing.
It is unfortuate that they call L2 switches SVI they should be called Management VI (MVI) to avoid confusion.
I believe you have intervlan routing because your trunk to the core is using proxy-arp on the core. You could switch off g0/1 and see if you still have inter vlan traffic
The proxy arp will be on your router or L3 switch. On the 2960 you have a trunk on 0/1 I assume there is router or L3 switch on the other end
show ip int gi0/0
GigabitEthernet0/0 is up, line protocol is up
Internet address is /20
Broadcast address is 255.255.255.255
Helper address is not set
Directed broadcast forwarding is disabled
Proxy ARP is enabled