02-22-2023
05:42 PM
- last edited on
02-28-2023
02:03 AM
by
Translator
Running into an issue that I cannot figure out and looking for help.
Cable modem (bridge mode) -> 1921 router -> 3750 switch -> computers
No devices can ping the
default gateway:10.5.104.1
The router config was built by another tech but worked at this location at one time which puzzles me as
10.5.104.1
is not anywhere in the config.
gi0/1.10 and placing 10.5.104.1on this interface, then the desktop can ping the
default gateway
Switch config
spanning-tree mode rapid-pvst
spanning-tree extend system-id
!
interface GigabitEthernet1/0/16
switchport access vlan 10
switchport mode access
switchport port-security maximum 2
switchport port-security mac-address sticky
speed 1000
storm-control broadcast level bps 10m
storm-control multicast level bps 10m
storm-control action shutdown
storm-control action trap
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/19
description AUTONOMOUS AP
switchport trunk encapsulation dot1q
switchport trunk native vlan 10
switchport trunk allowed vlan 2,5,10
switchport mode trunk
spanning-tree portfast trunk
!
interface GigabitEthernet1/0/43
switchport access vlan 5
switchport mode access
switchport port-security maximum 2
switchport port-security mac-address sticky
storm-control broadcast level bps 10m
storm-control multicast level bps 10m
storm-control action shutdown
storm-control action trap
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/46
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Vlan1
no ip address
!
interface Vlan2
ip address 10.2.104.6 255.255.255.0
ip helper-address 10.5.104.2
!
interface Vlan5
ip address 10.5.104.76 255.255.255.248
!
interface Vlan10
ip address 10.5.104.6 255.255.255.192
!
interface Vlan199
ip address 10.199.1.116 255.255.255.0
!
ip default-gateway 10.5.104.73
Router config
no ipv6 cef
no ip source-route
ip cef
!
interface Loopback2
ip address 10.5.104.240 255.255.255.255
!
interface GigabitEthernet0/0
ip address PUBLIC IP ADDRESS
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
no mop enabled
!
interface GigabitEthernet0/1
no ip address
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
no mop enabled
!
interface GigabitEthernet0/1.5
description Outside_MGMT
encapsulation dot1Q 5
ip address 10.5.104.73 255.255.255.248
ip nat inside
ip virtual-reassembly
!
interface GigabitEthernet0/1.7
encapsulation dot1Q 7
ip address 10.5.104.65 255.255.255.248
ip nat inside
ip virtual-reassembly
!
interface GigabitEthernet0/1.8
description Guest Wireless
encapsulation dot1Q 2
ip address 10.2.104.1 255.255.255.0
ip nat inside
ip virtual-reassembly
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip nat inside source list 103 interface GigabitEthernet0/0 overload
ip route 0.0.0.0 0.0.0.0 10.5.104.1
Thank you for your help.
Solved! Go to Solution.
02-25-2023
02:23 AM
- last edited on
02-28-2023
02:23 AM
by
Translator
Hello
You have quite a few mistakes in this configuration
- As the the router is performing the intervlan routing then you don't need any L3 addressing on the switch
- Missing l3 addressing on the router for vlan 10,199
- The router is performing NAT calling an
access-list
that is none existent
- Your default route is pointing to an interface ip residing on the switch
router
no ip route 0.0.0.0 0.0.0.0 10.5.104.1
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 <public ip next hop>
or
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 dhcp
interface GigabitEthernet0/1.10
encapsulation dot1Q 10
ip address 10.5.104.6 255.255.255.192
ip nat inside
interface GigabitEthernet0/1.199
encapsulation dot1Q 199
ip address 10.199.1.116 255.255.255.0
ip nat inside
access-list 103 permit ip 10.5.104.72 0.0.0.7 any
access-list 103 permit ip 10.5.104.64 0.0.0.7 any
access-list 103 permit ip 10.5.104.0 0.0.0.63 any
access-list 103 permit ip 10.2.104.0 0.0.0.255 any
access-list 103 permit ip 10.199.1.0 0.0.0.255 any
switch
config t
no interface Vlan2
no interface Vlan5
no interface Vlan10
no interface Vlan199
no ip routing
vlan 2,5,7,10,199
int vlan 5
ip address 10.5.104.74 255.255.255.248
Edited- forgot to mention the port on the switch that connects to router needs to be a trunk port
02-22-2023
06:45 PM
- last edited on
02-28-2023
02:07 AM
by
Translator
Hello
IP 10.5.104.1
can be assumed to be located on the cable modem.
This can be deduced by the next hop IP of the configured default route.
ip nat inside source list 103 interface GigabitEthernet0/0 overload
ip route 0.0.0.0 0.0.0.0 10.5.104.1
The ping to that IP will not be successful because the cable modem should not have a route configured for internal routes, the ones behind the router.
When you use RoaS, it is normal that the physical interface does not have an IP configured, since the addressing is housed in the sub interfaces.
Regards
02-22-2023
10:47 PM
- last edited on
02-28-2023
02:19 AM
by
Translator
No devices can ping the
default gateway:10.5.104.1
The router config was built by another tech but worked at this location at one time which
puzzles me as 10.5.104.1
is not anywhere in the config. << - this means this was not working ? or is this working still ?
There are lot of tweaks required in the config: example :
ip address PUBLIC IP ADDRESS (is this fixed IP address ?) and is this from same range 10.5.104.X ?
you have NAT statement but we did not see Access-list 103 content ?
ip nat inside source list 103 interface GigabitEthernet0/0 overload
you have 10.2.X and 10.5.X public IP address is this allocated by ISP to you ?
Not sure why you need Loopback interface here ?
You have VLAN tagged 5 7 8, but on the switch we see only VLAN 5 ? ( do you need rest of the VLAN ?)
SWITCH :
If the switch act as Layer 2, you can use
default gateway.
if the switch looks to the Routing function, you need to enable IP routing and change from
default gateway
to, IP route x.x.x.x statement.
02-23-2023
03:48 AM
- last edited on
02-28-2023
02:20 AM
by
Translator
The outside router interface is using a static public IP to talk to the modem, it is not using
10.5.104.1
I removed the IP when sharing the config.
02-24-2023 06:07 PM
ok what is the issue now ?
02-25-2023
02:23 AM
- last edited on
02-28-2023
02:23 AM
by
Translator
Hello
You have quite a few mistakes in this configuration
- As the the router is performing the intervlan routing then you don't need any L3 addressing on the switch
- Missing l3 addressing on the router for vlan 10,199
- The router is performing NAT calling an
access-list
that is none existent
- Your default route is pointing to an interface ip residing on the switch
router
no ip route 0.0.0.0 0.0.0.0 10.5.104.1
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 <public ip next hop>
or
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 dhcp
interface GigabitEthernet0/1.10
encapsulation dot1Q 10
ip address 10.5.104.6 255.255.255.192
ip nat inside
interface GigabitEthernet0/1.199
encapsulation dot1Q 199
ip address 10.199.1.116 255.255.255.0
ip nat inside
access-list 103 permit ip 10.5.104.72 0.0.0.7 any
access-list 103 permit ip 10.5.104.64 0.0.0.7 any
access-list 103 permit ip 10.5.104.0 0.0.0.63 any
access-list 103 permit ip 10.2.104.0 0.0.0.255 any
access-list 103 permit ip 10.199.1.0 0.0.0.255 any
switch
config t
no interface Vlan2
no interface Vlan5
no interface Vlan10
no interface Vlan199
no ip routing
vlan 2,5,7,10,199
int vlan 5
ip address 10.5.104.74 255.255.255.248
Edited- forgot to mention the port on the switch that connects to router needs to be a trunk port
02-25-2023 06:46 AM
Thanks for your reply Paul. I have already fixed this issue however I was just looking for confirmation that this config would not work as another tech built this and I wanted to make sure I didn’t miss anything.
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