10-31-2014 12:18 PM - edited 03-05-2019 12:05 AM
Can I connect a CISCO 2921 Router to a Wan through one of the gig ports or I need an EHWIC to do this?
10-31-2014 12:28 PM
You can definitely use one of the GigabitEthernet ports. Using one for WAN and the others for LAN/DMZ functionality is a fairly standard configuration for those routers.
10-31-2014 02:10 PM
Thank you. I cannot get it to work. Do you have any configuration example for the WAN side, that you would like to share? Thank you
10-31-2014 02:41 PM
Hi Tristan,
If you can, please describe the issue with some more details.
Regards,
Aref
11-02-2014 07:50 PM
We just bought two CISCO 2921 for my workplace. I am trying to learn how to set them up. We have been using Netgear for years. Our network has grown and Netgears are not enough anymore.
So I have a lab where I have a Netgear FVX538 connected to the Internet. Netgear LAN configuration is 172.18.0.1 255.255.255.0
I connected the CISCO to one of the LAN ports in the NETGEAR through gig 0/0. See configuration below.
I have connected a LAPTOP to gig 0/1, but it does not get to connect to the Internet. Another laptop, which is connected directly to NETGEAR cannot ping the CISCO Router
Using 2272 out of 262136 bytes
! Last configuration change at 19:30:41 PCT Sun Nov 2 2014
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
hostname CISCO-2921-Router-Elementary
!
boot-start-marker
boot-end-marker
!
no aaa new-model
memory-size iomem 25
clock timezone PCT -8 0
!
ip cef
!
no ip dhcp conflict logging
ip dhcp excluded-address 172.18.1.1 172.18.1.99
ip dhcp excluded-address 172.18.2.1 172.18.2.99
ip dhcp excluded-address 172.18.3.1 172.18.3.99
!
ip dhcp pool 0
network 172.18.2.0 255.255.255.0
domain-name elsolacademy.net
dns-server 172.18.0.228
default-router 172.18.1.1
lease 30
!
!
!
no ip domain lookup
ip host Netgear-FVX538 172.18.0.1
ip name-server 172.18.0.228
ip name-server 209.18.47.61
ip name-server 209.18.47.62
no ipv6 cef
multilink bundle-name authenticated
!
crypto pki trustpoint TP-self-signed-969957288
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-969957288
revocation-check none
rsakeypair TP-self-signed-969957288
!
crypto pki certificate chain TP-self-signed-969957288
certificate self-signed 01 nvram:IOS-Self-Sig#3.cer
license udi pid CISCO2921/K9 sn FGL175310DP
!
!
interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
description Internet
ip address 172.18.1.1 255.255.255.0
ip helper-address 172.18.0.1
ip helper-address 24.199.49.77
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address 172.18.2.1 255.255.255.0
duplex auto
speed auto
!
interface GigabitEthernet0/2
ip address 172.18.3.1 255.255.255.0
duplex auto
speed auto
!
router rip
network 172.18.0.0
!
ip default-gateway 172.18.0.1
ip forward-protocol nd
!
no ip http server
ip http secure-server
!
ip route 172.18.1.0 255.255.255.0 172.18.0.1
ip route 172.18.2.0 255.255.255.0 GigabitEthernet0/0
ip route 172.18.3.0 255.255.255.0 GigabitEthernet0/0
!
control-plane
!
line con 0
exec-timeout 0 0
logging synchronous
line aux 0
password brilla2012
line 2
no activation-character
no exec
transport preferred none
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line vty 0 4
password brilla2012
login
transport input all
!
scheduler allocate 20000 1000
!
end
10-31-2014 02:47 PM
There are many different ways it could be configured depending on the ISP and te technology being used. Do you have any details on what kind of WAN connection you're using?
11-02-2014 07:51 PM
We just bought two CISCO 2921 for my workplace. I am trying to learn how to set them up. We have been using Netgear for years. Our network has grown and Netgears are not enough anymore.
So I have a lab where I have a Netgear FVX538 connected to the Internet. Netgear LAN configuration is 172.18.0.1 255.255.255.0
I connected the CISCO to one of the LAN ports in the NETGEAR through gig 0/0. See configuration below.
I have connected a LAPTOP to gig 0/1, but it does not get to connect to the Internet. Another laptop, which is connected directly to NETGEAR cannot ping the CISCO Router
Using 2272 out of 262136 bytes
! Last configuration change at 19:30:41 PCT Sun Nov 2 2014
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
hostname CISCO-2921-Router-Elementary
!
boot-start-marker
boot-end-marker
!
no aaa new-model
memory-size iomem 25
clock timezone PCT -8 0
!
ip cef
!
no ip dhcp conflict logging
ip dhcp excluded-address 172.18.1.1 172.18.1.99
ip dhcp excluded-address 172.18.2.1 172.18.2.99
ip dhcp excluded-address 172.18.3.1 172.18.3.99
!
ip dhcp pool 0
network 172.18.2.0 255.255.255.0
domain-name elsolacademy.net
dns-server 172.18.0.228
default-router 172.18.1.1
lease 30
!
!
!
no ip domain lookup
ip host Netgear-FVX538 172.18.0.1
ip name-server 172.18.0.228
ip name-server 209.18.47.61
ip name-server 209.18.47.62
no ipv6 cef
multilink bundle-name authenticated
!
crypto pki trustpoint TP-self-signed-969957288
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-969957288
revocation-check none
rsakeypair TP-self-signed-969957288
!
crypto pki certificate chain TP-self-signed-969957288
certificate self-signed 01 nvram:IOS-Self-Sig#3.cer
license udi pid CISCO2921/K9 sn FGL175310DP
!
!
interface Embedded-Service-Engine0/0
no ip address
shutdown
!
interface GigabitEthernet0/0
description Internet
ip address 172.18.1.1 255.255.255.0
ip helper-address 172.18.0.1
ip helper-address 24.199.49.77
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address 172.18.2.1 255.255.255.0
duplex auto
speed auto
!
interface GigabitEthernet0/2
ip address 172.18.3.1 255.255.255.0
duplex auto
speed auto
!
router rip
network 172.18.0.0
!
ip default-gateway 172.18.0.1
ip forward-protocol nd
!
no ip http server
ip http secure-server
!
ip route 172.18.1.0 255.255.255.0 172.18.0.1
ip route 172.18.2.0 255.255.255.0 GigabitEthernet0/0
ip route 172.18.3.0 255.255.255.0 GigabitEthernet0/0
!
control-plane
!
line con 0
exec-timeout 0 0
logging synchronous
line aux 0
password brilla2012
line 2
no activation-character
no exec
transport preferred none
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
line vty 0 4
password brilla2012
login
transport input all
!
scheduler allocate 20000 1000
!
end
11-03-2014 05:20 AM
Hi,
Interface GigabitEthernet0/0 is setup with ip address 172.18.1.1 255.255.255.0, and Netgear has ip address 172.18.0.1 255.255.255.0, they are on different networks, you should correct the ip addresses, in addition the static routes are not appropriate, since those networks 172.18.1.0, 172.18.2.0 and 172.18.3.0 are connected to the Cisco router itself, you don't need them, also you should setup a default static route towards your gateway, it should be the Netgear ip address 172.18.0.1, finally you should ensure that the Netgear router knows how to get back to networks 172.18.2.0 and 172.18.3.0.
Regards,
Aref
11-03-2014 07:12 AM
First of all, thank you very much.
Let me see if I understood your answer.
1- Change the gig 0/0 address to 172.18.0.50 255.255.255.0. ?
2- IP routes should be ip route 172.18.2.0 255.255.255.0 172.18.0.1
Is that correct?
11-03-2014 08:09 AM
You are welcome Tristan.
Correct, g0/0 should be on the same subnet of the Negear, instead the default route should be towards any, example "ip route 0.0.0.0 0.0.0.0 172.18.0.1", and as mentioned before, Negear has to know how to get back to networks 172.18.2.x and 172.18.3.x., another solution would be to apply natting on the Cisco router so the Netgear would see all those networks as 172.18.0.x.
Please let me know if you still unclear.
Regards,
Aref
11-06-2014 04:53 PM
11-07-2014 08:34 AM
Hi Tristan,
That because the subinterfaces are not able to inter-route with the same physical interface where they are configured. Please try to do these modifications:
interface GigabitEthernet0/0
no ip address
no ip nat inside
!
interface GigabitEthernet0/0.1
encapsulation dot1Q 1 (assuming the native vlan on the trunk is vlan 1)
ip address 172.16.0.1 255.255.255.0
ip nat inside
Now on all other subinterfaces you should apply "ip nat inside", example:
interface GigabitEthernet0/0.15
ip nat inside
!
interface GigabitEthernet0/0.101
ip nat inside
and so on.
This static route is not needed and is not correct, because with that you are saying to route the traffic towards the network 172.16.0.0/16 out of g0/1 interface. It would not hurt in your case because the router would prefer the connected routes overy the static one, but please remove it:
no ip route 172.16.0.0 255.255.255.0 GigabitEthernet0/1
Regards,
Aref
11-07-2014 09:21 AM
Thank you very much
11-07-2014 09:41 AM
You are very welcome.
Please let me know if it did work properly.
Regards,
Aref
11-07-2014 11:03 AM
How can I define the Native Vlan or any other vlan in more than one interface? is that possible?
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