Inter VLAN routing on a BT Busness Hub

GJT · ‎06-07-2018

HI All,

I have a 3750 with a couple of vlans on it. I have a server 2012r2 with DCHP running and the vlans are routing between each other with DCHP working fine. I have a Cisco 1841 router with two routed ports configured to connect between the BT router and the 3750 switch. The machines on the vlans will not connect to the internet. I think this possibly a limitation of the BT router? I gather it is dropping the VLAN tagged packets?

I can ping from the pc to the switch and from the switch to the router and from the router to the BT Hub.

Apologies in advance for my lack of knowledge. Happy to post any config if someone is able to help.

Many thanks in advance.

Gary

Georg Pauwen · ‎06-07-2018

Hello,

I assume you have the router configured with subinterfaces for each Vlan ? Post the full config of your router...

GJT · ‎06-07-2018

Hi Georg,

Thanks for the swift reply. Any help or advice would appreciated.

Cheers

Gary

/////////////////////////////////////////////////////////////////////////////////////////////

Router Config

Current configuration : 880 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$H6oP$CFwzOISAqHZV/qoDUKRcw/
!
no aaa new-model
ip cef
!
!
!
!
ip name-server 192.168.1.254
vlan ifdescr detail
multilink bundle-name authenticated
!
!
archive
log config
hidekeys
!
!
!
!
!
interface FastEthernet0/0
description WAN
ip address 192.168.1.20 255.255.255.0
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
!
interface FastEthernet0/1
description LAN
ip address 192.168.2.254 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 192.168.1.254
!
!
no ip http server
!
!
!
control-plane
!
!
line con 0
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
end

/////////////////////////////////////////////////////////////////////////////////////////////////

Current configuration : 4675 bytes
!
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Switch
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
switch 1 provision ws-c3750e-48td
system mtu routing 1500
ip subnet-zero
ip routing
ip name-server 192.168.2.254
!
!
!
!
crypto pki trustpoint TP-self-signed-1349562240
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-1349562240
revocation-check none
rsakeypair TP-self-signed-1349562240
!
!
crypto pki certificate chain TP-self-signed-1349562240
certificate self-signed 01
3082023F 308201A8 A0030201 02020101 300D0609 2A864886 F70D0101 04050030
31312F30 2D060355 04031326 494F532D 53656C66 2D536967 6E65642D 43657274
69666963 6174652D 31333439 35363232 3430301E 170D3933 30333031 30303031
33355A17 0D323030 31303130 30303030 305A3031 312F302D 06035504 03132649
4F532D53 656C662D 5369676E 65642D43 65727469 66696361 74652D31 33343935
36323234 3030819F 300D0609 2A864886 F70D0101 01050003 818D0030 81890281
8100E03D 178ADD1C 3444FC75 6AF3F12B 81E523AA 0BBDFC47 83EF47BC E7F82EF2
53B40801 A9978FB6 7B04924D A8D29D5A E999C347 0DEDB050 88761231 30BABB67
A79E52A8 8FE296F9 674CDB30 E4678A99 E3BFE72A D42315ED E249C0A2 8CCE06C5
056BA1E9 15DE6A3E B4CB104C 82334E93 93947296 FEF6D85D D480A666 652B3E4C
924F0203 010001A3 67306530 0F060355 1D130101 FF040530 030101FF 30120603
551D1104 0B300982 07537769 7463682E 301F0603 551D2304 18301680 149C538D
2C74689F 40297895 4E6ECFA5 394E7C84 F0301D06 03551D0E 04160414 9C538D2C
74689F40 2978954E 6ECFA539 4E7C84F0 300D0609 2A864886 F70D0101 04050003
81810086 1904BF02 C512B13C FA084814 819FF391 6A15423D FDDB5E0B 2756C0B2
B31F01DF B72D7AD5 7A684149 7DBA1017 91AE472D B3A7C300 59CC7703 672EAFE4
D5FDB3AA 19363B75 913D8AAF B87B2460 197B598C F6F2EF4A 5840848B 90FD8208
F29683FD 1CF20553 0BE78F46 C92EB836 C35189EE 2D7CFFCC D1610372 FC3C37D3 2CFE3A
quit
license boot level ipbase
!
!
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
!
!
interface FastEthernet0
no ip address
no ip route-cache cef
no ip route-cache
no ip mroute-cache
shutdown
!
interface GigabitEthernet1/0/1
no switchport
ip address 192.168.2.1 255.255.255.0
!
interface GigabitEthernet1/0/2
switchport access vlan 2
spanning-tree portfast
!
interface GigabitEthernet1/0/3
switchport access vlan 2
spanning-tree portfast
!
interface GigabitEthernet1/0/4
switchport access vlan 3
spanning-tree portfast
!
interface GigabitEthernet1/0/5
!
interface GigabitEthernet1/0/6
!
interface GigabitEthernet1/0/7
!
interface GigabitEthernet1/0/8
!
interface GigabitEthernet1/0/9
!
interface GigabitEthernet1/0/10
!
interface GigabitEthernet1/0/11
!
interface GigabitEthernet1/0/12
!
interface GigabitEthernet1/0/13
!
interface GigabitEthernet1/0/14
!
interface GigabitEthernet1/0/15
!
interface GigabitEthernet1/0/16
!
interface GigabitEthernet1/0/17
!
interface GigabitEthernet1/0/18
!
interface GigabitEthernet1/0/19
!
interface GigabitEthernet1/0/20
!
interface GigabitEthernet1/0/21
!
interface GigabitEthernet1/0/22
!
interface GigabitEthernet1/0/23
!
interface GigabitEthernet1/0/24
!
interface GigabitEthernet1/0/25
!
interface GigabitEthernet1/0/26
!
interface GigabitEthernet1/0/27
!
interface GigabitEthernet1/0/28
!
interface GigabitEthernet1/0/29
!
interface GigabitEthernet1/0/30
!
interface GigabitEthernet1/0/31
!
interface GigabitEthernet1/0/32
!
interface GigabitEthernet1/0/33
!
interface GigabitEthernet1/0/34
!
interface GigabitEthernet1/0/35
!
interface GigabitEthernet1/0/36
!
interface GigabitEthernet1/0/37
!
interface GigabitEthernet1/0/38
!
interface GigabitEthernet1/0/39
!
interface GigabitEthernet1/0/40
!
interface GigabitEthernet1/0/41
!
interface GigabitEthernet1/0/42
!
interface GigabitEthernet1/0/43
!
interface GigabitEthernet1/0/44
!
interface GigabitEthernet1/0/45
!
interface GigabitEthernet1/0/46
!
interface GigabitEthernet1/0/47
!
interface GigabitEthernet1/0/48
!
interface GigabitEthernet1/0/49
!
interface GigabitEthernet1/0/50
!
interface GigabitEthernet1/0/51
!
interface GigabitEthernet1/0/52
!
interface TenGigabitEthernet1/0/1
!
interface TenGigabitEthernet1/0/2
!
interface Vlan1
ip address 192.168.2.2 255.255.255.0
shutdown
!
interface Vlan2
ip address 192.168.12.1 255.255.255.0
ip helper-address 192.168.12.10
!
interface Vlan3
ip address 192.168.11.1 255.255.255.0
ip helper-address 192.168.12.10
!
ip classless
ip route 0.0.0.0 0.0.0.0 192.168.2.254
ip http server
ip http secure-server
!
!
control-plane
!
!
line con 0
line vty 0 4
login
line vty 5 15
login
!
end

Georg Pauwen · ‎06-07-2018

Hello,

add the lines in bold below to your config:

interface FastEthernet0/0
description WAN
ip address 192.168.1.20 255.255.255.0
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
!
interface FastEthernet0/1
description LAN
ip address 192.168.2.254 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 192.168.1.254

!

ip nat inside source list 1 interface FastEthernet0/0 overload

!

access-list 1 permit 192.168.0.0 0.0.255.255

GJT · ‎06-07-2018

Hi

Pasted them in thanks, still no joy.

Kind regards

Gary

Georg Pauwen · ‎06-07-2018

Hello,

can you ping 192.168.1.20 from the Switch ?

ping 192.168.1.20 source 192.168.12.1
ping 192.168.1.20 source 192.168.11.1

Georg Pauwen · ‎06-07-2018

Hello,

on your router, add the two static routes below:

ip route 192.168.11.0 255.255.255.0 192.168.2.1

ip route 192.168.12.0 255.255.255.0 192.168.2.1