configuring a cisco 1941

[BLHenze]

I have a cisco 1941 with two Gigabit interfaces. Ge0/0 is 172.17.8.4 and Ge0/1 is 172.17.50.1. When telneted into the router I can ping everything on both networks but can't get past 172.17.8.1 and thus cannot go to the internet. Does anyone have any suggestions on getting past 172.17.8.1?

 

[unclerico]

do you have a default route on the router?? post your config

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)

 

[BLHenze]

Here's the config

Current configuration : 1241 bytes
!
! Last configuration change at 14:33:06 UTC Fri Oct 1 2010 by blhenze
!
version 15.0
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname EngineerRobo
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$Ajy8$qG5ECxSZIB8HvCOdtWK6t.
!
no aaa new-model
!
no ipv6 cef
ip source-route
ip cef
!
!
!
!
ip name-server 172.17.36.21
ip name-server 172.17.36.22
multilink bundle-name authenticated
!
!
!
license udi pid CISCO1941/K9 sn FTX1405Y569
!
!

!
!
!
!
!
!
interface GigabitEthernet0/0
ip address 172.17.8.4 255.255.255.0
ip helper-address 172.17.8.1
ip helper-address 172.17.36.21
ip helper-address 172.17.36.22
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address 172.17.50.1 255.255.255.0
ip helper-address 172.17.36.21
ip helper-address 172.17.36.22
ip helper-address 172.17.8.1
duplex auto
speed auto
!
router rip
network 172.17.0.0
!
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
!
!
!
!
control-plane
!
banner motd ^C
Warning!!!!! Unauthorized access is prohibited! ^C
!
line con 0
password freddy39
login
line aux 0
line vty 0 4
login local
!
scheduler allocate 20000 1000
end

 

[Viconsul]

As unclerico hinted you need a default route on the router or get a routing protocol to do it. Depending on how your network is setup it might be quicker and easier to have a default route point to your next hop (usually your isp router).

 

[BLHenze]

I've added the following lines to the script, but nothing has changed.

!
ip default-gateway 172.17.8.1
ip forward-protocol nd
!

 

[Viconsul]

You will need to add a default route something like
ip route 0.0.0.0 0.0.0.0 int Gi0/0 xxx.xxx.xxx.xxx (where xxx.xxx.xxx.xxx is your next hop router ip address)

 

[BLHenze]

Added the following in but nothing changed.

!
ip route 0.0.0.0 0.0.0.0 172.17.8.1
!

Would not accept on the interface.

 

[unclerico]

Can you get on the 8.1 router and try to ping?? Also, I want to verify that you are trying to ping from the 8.4 router and not a host on the .50 network

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)

 

[BLHenze]

My workstation is on the 172.17.8.x net. I telnet to the router (172.17.8.4 on Gi0/0). While in a telnet session, I can ping from the router anything on 172.17.8.x and 172.17.50.x. When I attempt to ping beyond 172.17.8.1 (like the DNS) it times out.

From the workstation, in a command prompt window, I can ping the DNS and places beyond. I just can't figure out why I'm not connecting to the internet from my classroom computers that are on the 172.17.50.x.

 

[brianinms]

The router that is 8.1 needs to have a route
for the 50 network and point it to 8.4.

 

[unclerico]

that's exactly where i was going next b.

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)

 

[BLHenze]

Thanks all, I will contact the IT guy in charge of the backbone and send him your conclusions. I have though all along that it was his "door" that wasn't swinging both ways.

 

[brianinms]

Might I add that the ip helper addresses are incorrectly configured as well. You only need them on the interface that faces your pc's which would be the G0/1. Additionally, the ip helper should only point to servers that are actually handing out dhcp. Is the router at 8.1 running dhcp?

 

[Quadratic]

Helper addresses aren't just DHCP relays. It's possible they are meant for another purpose (TFTP server, for example).

CCNP, CCDP

 

[brianinms]

Quad - Yes, I am aware the use of an ip helper isn't restricted to just dhcp. However, the ip helper statements are still misconfigured. In my 11 years of Cisco networking I have yet to see an ip-helper directed at anything other than a DHCP server.

 

[BLHenze]

From a telnet session inside 172.17.8.4 (GI0/0) I now can ping anywhere on the net. However, when I attempt to ping the 172.17.50.1 (Gi0/1) from the 172.17.8.x I get the following:

H:\>ping 172.17.8.4

Pinging 172.17.8.4 with 32 bytes of data:

Reply from 172.17.8.4: bytes=32 time<1ms TTL=255
Reply from 172.17.8.4: bytes=32 time<1ms TTL=255
Reply from 172.17.8.4: bytes=32 time<1ms TTL=255
Reply from 172.17.8.4: bytes=32 time<1ms TTL=255

Ping statistics for 172.17.8.4:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

H:\>ping 172.17.50.1

Pinging 172.17.50.1 with 32 bytes of data:

Request timed out.
Reply from 172.17.8.1: Destination host unreachable.
Request timed out.
Reply from 172.17.8.1: Destination host unreachable.

Ping statistics for 172.17.50.1:
Packets: Sent = 4, Received = 2, Lost = 2 (50% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

Any suggestions?

 

[unclerico]

is the interface up??

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)

 

[BLHenze]

yes - my classroom computers (on 172.17.50.x) ping to 172.17.8.4 but can't get to 172.17.8.1

 

[BLHenze]

Here is additional information that may be of help.

EngineerRobo#show ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, + - replicated route

Gateway of last resort is 172.17.8.1 to network 0.0.0.0

S* 0.0.0.0/0 [1/0] via 172.17.8.1
172.17.0.0/16 is variably subnetted, 4 subnets, 2 masks
C 172.17.8.0/24 is directly connected, GigabitEthernet0/0
L 172.17.8.4/32 is directly connected, GigabitEthernet0/0
C 172.17.50.0/24 is directly connected, GigabitEthernet0/1
L 172.17.50.1/32 is directly connected, GigabitEthernet0/1
EngineerRobo#show ip protocols
*** IP Routing is NSF aware ***

Routing Protocol is "rip"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Sending updates every 30 seconds, next due in 14 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Triggered RIP Key-chain
GigabitEthernet0/0 1 1 2
GigabitEthernet0/1 1 1 2
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
172.17.0.0
Routing Information Sources:
Gateway Distance Last Update
Distance: (default is 120)

EngineerRobo#show ip arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 172.17.8.1 0 0009.7c32.7e09 ARPA GigabitEthernet0/0
Internet 172.17.8.4 - 68ef.bd57.5d00 ARPA GigabitEthernet0/0
Internet 172.17.8.236 0 0012.3f47.26fe ARPA GigabitEthernet0/0
Internet 172.17.8.244 18 0027.0e1d.a00b ARPA GigabitEthernet0/0
Internet 172.17.50.1 - 68ef.bd57.5d01 ARPA GigabitEthernet0/1
Internet 172.17.50.5 1 0013.f7ca.5c0e ARPA GigabitEthernet0/1
Internet 172.17.50.10 0 0023.ebb0.d46c ARPA GigabitEthernet0/1
Internet 172.17.50.11 25 0027.0e1d.a043 ARPA GigabitEthernet0/1
Internet 172.17.50.101 89 0000.74ad.d7d1 ARPA GigabitEthernet0/1
Internet 172.17.50.105 0 0080.878b.f328 ARPA GigabitEthernet0/1
Internet 172.17.50.201 1 0027.0e1d.a045 ARPA GigabitEthernet0/1
Internet 172.17.50.202 9 0027.0e1d.a005 ARPA GigabitEthernet0/1
Internet 172.17.50.203 30 0027.0e04.c56d ARPA GigabitEthernet0/1
Internet 172.17.50.204 38 0027.0e04.c574 ARPA GigabitEthernet0/1
Internet 172.17.50.205 27 0027.0e1d.9fef ARPA GigabitEthernet0/1
Internet 172.17.50.207 25 0027.0e1d.9ff3 ARPA GigabitEthernet0/1
Internet 172.17.50.208 31 0027.0e1d.9ffe ARPA GigabitEthernet0/1
Internet 172.17.50.209 1 0027.0e1d.a040 ARPA GigabitEthernet0/1
Internet 172.17.50.210 1 0027.0e1d.9faa ARPA GigabitEthernet0/1
Internet 172.17.50.213 30 0027.0e1d.a042 ARPA GigabitEthernet0/1
Internet 172.17.50.214 27 0027.0e1d.a05b ARPA GigabitEthernet0/1
Internet 172.17.50.215 0 0027.0e1d.9ff8 ARPA GigabitEthernet0/1
Internet 172.17.50.216 25 0027.0e1d.9fe1 ARPA GigabitEthernet0/1
Internet 172.17.50.217 3 0027.0e1d.a02f ARPA GigabitEthernet0/1
Internet 172.17.50.218 8 0027.0e1d.a004 ARPA GigabitEthernet0/1
Internet 172.17.50.219 79 0027.0e04.c53f ARPA GigabitEthernet0/1
Internet 172.17.50.220 148 0027.0e1d.a00b ARPA GigabitEthernet0/1
Internet 172.17.50.221 25 0027.0e1d.9fc9 ARPA GigabitEthernet0/1
Internet 172.17.50.222 32 0027.0e1d.9fc6 ARPA GigabitEthernet0/1
Internet 172.17.50.223 24 0027.0e1d.9fda ARPA GigabitEthernet0/1
Internet 172.17.50.224 27 0027.0e1d.a049 ARPA GigabitEthernet0/1
Internet 172.17.50.240 1 00d0.b80c.01d6 ARPA GigabitEthernet0/1
Internet 172.17.50.250 0 0015.17b9.e498 ARPA GigabitEthernet0/1
EngineerRobo#

 

[unclerico]

can you get onto the 8.1 router?? it says that the host is unreachable as opposed to destination network unreachable which tells me 8.1 knows about the 172.17.50/24 network. to me the problem still lies with the 8.1 router.

I hate all Uppercase... I don't want my groups to seem angry at me all the time! =)
- ColdFlame (vbscript forum)