03-14-2012 01:27 PM - edited 03-07-2019 05:34 AM
I am very new at this, but we have a 2801 router running 12.4, a 3560 that acts as the "Core" switch, and a bunch of remote 2960G's that connect via fiber to different buildings.
I am tasked to VLAN this network to reduce broadcast traffic. I started by setting up a VLAN 169 on the "3560" named the VTP domain, changed to version 2, and no password. THe Core switch and remote switch can share the VTP info, I HAD the Router seeing it too (able to ping 192.168.169.1) until I changed the "Domain" and "VTP Version"
The switches see each other fine, my problem is the Router sub interface 0/0.169 I cannot get to see the VTP domain. I imagine because I don’t have a "Trunk port" set on the Router, but the option is not there. Meaning I cannot do a "switchport mode trunk" on it. The only thing I see is to make it:
TCRouter(config-subif)#encapsulation dot1Q 169 native
But, my "int fas 0/0" is used now as the main interface for our "only" network 192.168.0.0, do I need to turn this over to a subinterface and make it "Native" then the difference of the subinterfaces will advertise?
Help......
Here is some of my conf:
Core SW:
TCCoreSW#sh vtp status
VTP Version : running VTP2
Configuration Revision : 8
Maximum VLANs supported locally : 1005
Number of existing VLANs : 10
VTP Operating Mode : Server
VTP Domain Name : Tecnico
VTP Pruning Mode : Disabled
VTP V2 Mode : Enabled
VTP Traps Generation : Disabled
MD5 digest : 0x6B 0x93 0x23 0xD8 0x62 0x65 0x94 0xCF
Configuration last modified by 192.168.0.42 at 3-14-12 18:21:58
Local updater ID is 192.168.0.15 on interface Vl100 (lowest numbered VLAN interface found)
Vlan169 is up, line protocol is up
Internet address is 192.168.169.2/24
Broadcast address is 255.255.255.255
Address determined by setup command
MTU is 1500 bytes
Helper address is 192.168.0.16
Directed broadcast forwarding is disabled
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Local Proxy ARP is disabled
Security level is default
Split horizon is enabled
ICMP redirects are always sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP CEF switching is enabled
IP CEF switching turbo vector
IP Null turbo vector
IP multicast fast switching is enabled
IP multicast distributed fast switching is disabled
IP route-cache flags are Fast, CEF
Router Discovery is disabled
IP output packet accounting is disabled
IP access violation accounting is disabled
TCP/IP header compression is disabled
RTP/IP header compression is disabled
Probe proxy name replies are disabled
Policy routing is disabled
Network address translation is disabled
BGP Policy Mapping is disabled
Output features: Check hwidb
WCCP Redirect outbound is disabled
WCCP Redirect inbound is disabled
WCCP Redirect exclude is disabled
Router:
VTP Version : 2
Configuration Revision : 1
Maximum VLANs supported locally : 19
Number of existing VLANs : 5
VTP Operating Mode : Server
VTP Domain Name : Tecnico
VTP Pruning Mode : Enabled
VTP V2 Mode : Enabled
VTP Traps Generation : Disabled
MD5 digest : 0x0D 0xFD 0x5D 0xFD 0x55 0xA8 0x6F 0x6D
Configuration last modified by 192.168.0.1 at 3-14-12 19:26:26
Local updater ID is 192.168.0.1 on interface Fa0/0 (first interface found)
Preferred interface name is 192.168.0.1
TCRouter#sh interfaces fastEthernet 0/0.169
FastEthernet0/0.169 is up, line protocol is up
Hardware is Gt96k FE, address is 0023.33b5.ecd4 (bia 0023.33b5.ecd4)
Internet address is 192.168.169.1/24
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 169.
ARP type: ARPA, ARP Timeout 04:00:00
Last clearing of "show interface" counters never
Solved! Go to Solution.
03-14-2012 01:56 PM
If you have multiple vlans that need to reach the router on interface Fa0/0, than you need to create a sub-interface for each vlan. You would need to remove the current IP from the main interface and apply it to a sub-interface:
encapsulation dot1Q 169
encapsulation dot1Q 170
and so on
Doing this will require an outage window.
HTH
03-14-2012 01:56 PM
If you have multiple vlans that need to reach the router on interface Fa0/0, than you need to create a sub-interface for each vlan. You would need to remove the current IP from the main interface and apply it to a sub-interface:
encapsulation dot1Q 169
encapsulation dot1Q 170
and so on
Doing this will require an outage window.
HTH
03-15-2012 05:47 AM
Thanks for the prompt response, I will work that in today. Is there a need for the "native" command?
03-15-2012 06:55 AM
Hi Andrew,
If you want to recieve and forward data from the native vlan you should create an appropriate subinterface for it. What native vlan are you using?
If you are using vlan 169 as native you should do similar:
TCRouter(config)#interface fa0/0.169
TCRouter(config-subif)#encapsulation dot1Q 169 native
TCRouter(config-subif)#ip address YOUR_IP YOUR_MASK
Best regards,
Jan
03-15-2012 07:28 AM
Hi,
there is one workaround available for a case you've got no maintenence window available.
You could leave the IP address used for the native VLAN on the main interface.
And create subinterfaces for the other (tagged) VLANs only.
This is a trick coming from the old days when "native" keyword was not available yet.
It's not a nice configuration but works.
If you've got a maintenance window available for a short outage, creating a subinterface with encapsulation ... native is definitely recommended though.
HTH,
Milan
03-15-2012 09:17 AM
Beautiful, I have changed the sub interface to my network 192.168.0.0 and I can now ping my other VLAN.
Still the same problem is I cannot seem to get the VTP to update the router, but the switches will talk to each other, this seemed to occur when I swapped the router to version 2. Do I NEED a password?
03-15-2012 11:04 AM
Answering my own question here for anyone else that might have this problem. Again I am new at this.
I have my router interface connected to my core switch on port 0/3, which is not configured as a "switchport trunk encapsulation dot1q" then "switchport mode trunk" finally "switchport trunk allowed vlan all".
I am not sure if this will drop connections, so I will schedule down time, I inherited this "setup" which I am working to fix, thanks for the prompt responses.
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