I can't issue configurating a cisco 2611 (2 ethernet 10Mbits) with my "special" modem from my Internet Service Provider.
My modem identify itself to my provider. It as an ethernet connection and i plug it in the Ethernet0/1 of the Cisco 2611 I connect my lan to the ethernet0/0 with the Ip
192.168.0.244/255.255.255.0
The problem is that the ethernet0/1 is in DHCP and get well an IP address and the good mask but not the gateway of my internet provider....
If i make (in configure terminal) ip route 0.0.0.0 0.0.0.0 x.y.z.254 (where x.y.z.254 is the provider's router when i get a x.y.z.t ip address) , i can surf for 2 minutes and then nothing works again :-( It's probably because of the dhcp lease , because if i make for the ethernet0/1 interface ip address X.Y.Z.T 255.255.255.0 where X.Y.Z.T is the address obtain from my ISP and then ip route 0.0.0.0 0.0.0.0 x.y.z.254 i can surf until my ISP give me another address...
What's wrong ? How can the 2611 get the default gateway each time my ISP change my IP address Thanks for your help .... Sam
Here is my configuration : xxxx.free.fr#show run Building configuration...
Current configuration : 1090 bytes ! version 12.3 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname xxxx.free.fr ! boot-start-marker boot-end-marker ! enable password xxxxxx ! no aaa new-model ip subnet-zero ip cef ! ! no ip domain lookup ! ip audit notify log ip audit po max-events 100 ip dhcp-client network-discovery informs 2 discovers 2 period 15 no ftp-server write-enable ! ! ! ! interface Ethernet0/0 description connected to EthernetLAN ip address 192.168.0.244 255.255.255.0 ip nat inside half-duplex ! interface Ethernet0/1 description connected to Internet ip address dhcp ip nat outside half-duplex ! router rip version 1 passive-interface Ethernet0/1 network 192.168.0.0 no auto-summary ! ip nat inside source list 1 interface Ethernet0/1 overload no ip http server ip classless ip route 0.0.0.0 0.0.0.0 Ethernet0/1 ! ! access-list 1 permit 192.168.0.0 0.0.0.255 snmp-server community public RO snmp-server enable traps tty ! line con 0 exec-timeout 0 0 password xxxxxxxx login line aux 0 line vty 0 4 password xxxxxxx login ! ! ! end
Then do "debug dhcp detail", shut/no shut E0/1 and see if the ISP gives you a gateway/next hop router address. If it does the router should make a default route that address as the next hop.
Here what i get ! As you can see, the isp give a gateway but the cisco seem's can't do anything with it ... As you can see i tried to ping, but without success ! What's wrong ? Thanks for your help Sam
*****
toto.free.fr#configure t Enter configuration commands, one per line. End with CNTL/Z.
00:02:38: DHCP: Lease Seconds: 600 Renewal secs: 60 Rebind secs: 600
00:02:38: DHCP: Server ID Option: 82.252.130.254
00:02:38: DHCP: offer received from 82.252.130.254
00:02:38: DHCP: SRequest attempt # 1 for entry:
00:02:38: Temp IP addr: 82.252.130.186 for peer on Interface: Ethernet0/1
00:02:38: Temp sub net mask: 255.255.255.0
00:02:38: DHCP Lease server: 82.252.130.254, state: 2 Requesting
00:02:38: DHCP transaction id: 27CFD
00:02:38: Lease: 600 secs, Renewal: 0 secs, Rebind: 0 secs
00:02:38: Next timer fires after: 00:00:01
00:02:38: Retry count: 1 Client-ID: cisco-0008.21ea.aa81-Et0/1
00:02:38: Hostname: toto.free.fr
00:02:38: DHCP: SRequest- Server ID option: 82.252.130.254
00:02:38: DHCP: SRequest- Requested IP addr option: 82.252.130.186
00:02:38: DHCP: SRequest placed lease len option: 600
00:02:38: DHCP: SRequest: 322 bytes
00:02:38: DHCP: SRequest: 322 bytes
00:02:38: B'cast on Ethernet0/1 interface from 0.0.0.0
00:02:38: DHCP: Received a BOOTREP pkt
00:02:38: DHCP: Scan: Message type: DHCP Ack
00:02:38: DHCP: Scan: Server ID Option: 82.252.130.254 = 52FC82FE
00:02:38: DHCP: Scan: Renewal time: 60
00:02:38: DHCP: Scan: Rebind time: 600
00:02:38: DHCP: Scan: Lease Time: 600
00:02:38: DHCP: Scan: Subnet Address Option: 255.255.255.0
00:02:38: DHCP: Scan: Router Option: 82.252.130.254
00:02:38: DHCP: Scan: DNS Name Server Option: 213.228.0.212,
212.27.32.177
00:02:38: DHCP: rcvd pkt source: 82.252.130.254, destination:
255.255.255.255
00:02:38: UDP sport: 43, dport: 44, length: 556
00:02:38: DHCP op: 2, htype: 1, hlen: 6, hops: 0
00:02:38: DHCP server identifier: 82.252.130.254
00:02:38: xid: 27CFD, secs: 0, flags: 0
00:02:38: client: 0.0.0.0, your: 82.252.130.186
00:02:38: srvr: 82.252.130.254, gw: 0.0.0.0
00:02:38: options block length: 308
00:02:38: DHCP Ack Message
00:02:38: DHCP: Lease Seconds: 600 Renewal secs: 60 Rebind secs: 600
00:02:38: DHCP: Server ID Option: 82.252.130.254
00:02:40: %LINK-3-UPDOWN: Interface Ethernet0/1, changed state to up
00:02:41: %LINEPROTO-5-UPDOWN: Line protocol on Interface Ethernet0/1, changed state to up
00:02:41: DHCP: Applying DHCP options:
00:02:41: DHCP: Releasing ipl options:
00:02:41: Setting default_gateway to 82.252.130.254
00:02:41: Adding default route 82.252.130.254
00:02:41: Adding DNS server address 213.228.0.212
00:02:41: Adding DNS server address 212.27.32.177
00:02:41: DHCP Client Pooling: ***Allocated IP address: 82.252.130.186
00:02:41: Allocated IP address = 82.252.130.186 255.255.255.0
00:02:48: %SYS-5-CONFIG_I: Configured from console by console toto.free.fr#
00:02:54: DHCP: QScan: Purging entry
00:02:54: DHCP: deleting entry 818050AC 0.0.0.0 from list
00:02:54: Temp IP addr: 0.0.0.0 for peer on Interface: unknown
00:02:54: Temp sub net mask: 255.255.255.0
00:02:54: DHCP Lease server: 82.252.130.254, state: 8 Purging
00:02:54: DHCP transaction id: 6FA3
00:02:54: Lease: 600 secs, Renewal: 60 secs, Rebind: 600 secs
00:02:54: Temp default-gateway addr: 82.252.130.254
00:02:54: No timer running
00:02:54: Retry count: 0 Client-ID:
00:02:54: Hostname: toto.free.fr toto.free.fr#ping 212.27.32.177
Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 212.27.32.177, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) toto.free.fr#ping 82.252.130.254
Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 82.252.130.254, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) toto.free.fr#
00:03:41: DHCP: Lease Seconds: 600 Renewal secs: 60 Rebind secs: 600
00:03:41: DHCP: Server ID Option: 82.252.130.254
00:03:41: DHCP: Applying DHCP options:
00:03:41: DHCP: Releasing ipl options:
00:03:41: Setting default_gateway to 82.252.130.254
00:03:41: Adding DNS server address 213.228.0.212
00:03:41: Adding DNS server address 212.27.32.177
00:03:41: DHCP Client Pooling: ***Allocated IP address: 82.252.130.186 toto.free.fr#ping 82.252.130.254
Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 82.252.130.254, timeout is 2 seconds: ..... Success rate is 0 percent (0/5) toto.free.fr#ping 212.27.32.177
Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 212.27.32.177, timeout is 2 seconds: ..... Success rate is 0 percent (0/5)
Whoops! I just spent 20 minutes tidying up and studying the debugs from pref. That'll learn me :)
ip route 0.0.0.0 0.0.0.0 Ethernet0/1 relies on the next hop,
82.252.130.254, proxy arping for the destination address. If it doesn't you are out of luck.
The default route installed by the dhcp client also has a high administrative distance, 254 by default, which means the any other default route with a lower admin distance will go in the routing table ahead of it.
So in your case you had a static default route, admin distance = 0, that probably wasn't working because the next hop wasn't proxy arping, and the default route from the dhcp didn't go in the routing table because its admin distance was > 0.
I'm not sure to understand all ... (my english is not very good) Are you telling me that i have no other choice than suppress the line: ip route 0.0.0.0 0.0.0.0 ethernet0/1 ? Thanks again, and i confirm with now it works well.
( I have now another problem with access-list , but i write another post because it's different from this problem)
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