2621 router only grabbing local IP from ISP (cox cable)

[kutsunee]

Right now I've got my pix 501 behind my modem and my 2621 behind my PIX. Each setup to use PAT.

I wanted to remove the pix from the network and just use the 2621 to connect to the internet. I have a feeling that the dhcp server at cox thinks for some reason my device is part of their internal network, because it refuses to give the 2621 a publicly routed IP.

here is my debug dhcp detail:
00:39:01: DHCP: Received a BOOTREP pkt Not for us..: xid: 0x6A222CE
00:39:01: DHCP: Received a BOOTREP pkt Not for us..: xid: 0x6A222CE
00:39:02: DHCP: Received a BOOTREP pkt Not for us..: xid: 0x1124
00:39:03: DHCP: Received a BOOTREP pkt Not for us..: xid: 0x4595BE81
00:39:06: DHCP: QScan: Purging entry
00:39:06: DHCP: deleting entry 80F1DA8C 0.0.0.0 from list
00:39:06: Temp IP addr: 0.0.0.0 for peer on Interface: unknown
00:39:06: Temp sub net mask: 0.0.0.0
00:39:06: DHCP Lease server: 0.0.0.0, state: 8 Purging
00:39:06: DHCP transaction id: 974
00:39:06: Lease: 0 secs, Renewal: 0 secs, Rebind: 0 secs
00:39:06: No timer running
00:39:06: Retry count: 0 Client-ID:
00:39:06: DHCP: allocate request
00:39:06: DHCP: zapping entry in DHC_PURGING state for Fa0/0
00:39:06: DHCP: new entry. add to queue
00:39:06: DHCP: SDiscover attempt # 1 for entry:
00:39:06: Temp IP addr: 0.0.0.0 for peer on Interface: FastEthernet0/0
00:39:06: Temp sub net mask: 0.0.0.0
00:39:06: DHCP Lease server: 0.0.0.0, state: 1 Selecting
00:39:06: DHCP transaction id: 976
00:39:06: Lease: 0 secs, Renewal: 0 secs, Rebind: 0 secs
00:39:06: Next timer fires after: 00:00:03
00:39:06: Retry count: 1 Client-ID: cisco-0009.e899.0de0-Fa0/0
00:39:06: DHCP: SDiscover: sending 306 byte length DHCP packet
00:39:06: DHCP: SDiscover 306 bytes
00:39:06: B'cast on FastEthernet0/0 interface from 0.0.0.0
00:39:07: DHCP: Received a BOOTREP pkt
00:39:07: DHCP: Scan: Message type: DHCP Offer
00:39:07: DHCP: Scan: Server ID Option: 172.19.97.16 = AC136110
00:39:07: DHCP: Scan: Lease Time: 86400
00:39:07: DHCP: Scan: Subnet Address Option: 255.255.252.0
00:39:07: DHCP: Scan: DNS Name Server Option: 68.105.28.12, 68.105.29.12, &68.105.28.11&
00:39:07: DHCP: Scan: Domain Name: sd.cox.net
00:39:07: DHCP: Scan: Router Option: 10.136.24.1
00:39:07: DHCP: rcvd pkt source: 10.136.16.1, destination: 255.255.255.255
00:39:07: UDP sport: 43, dport: 44, length: 318
00:39:07: DHCP op: 2, htype: 1, hlen: 6, hops: 1
00:39:07: DHCP server identifier: 172.19.97.16
00:39:07: xid: 976, secs: 0, flags: 8000
00:39:07: client: 0.0.0.0, your: 10.136.27.86
00:39:07: srvr: 172.19.97.16, gw: 10.136.16.1
00:39:07: options block length: 70

00:39:07: DHCP Offer Message Offered Address: 10.136.27.86
00:39:07: DHCP: Lease Seconds: 86400
00:39:07: DHCP: Server ID Option: 172.19.97.16
00:39:07: DHCP: offer received from 172.19.97.16
00:39:07: DHCP: SRequest attempt # 1 for entry:
00:39:07: Temp IP addr: 10.136.27.86 for peer on Interface: FastEthernet0/0
00:39:07: Temp sub net mask: 255.255.252.0
00:39:07: DHCP Lease server: 172.19.97.16, state: 2 Requesting
00:39:07: DHCP transaction id: 976
00:39:07: Lease: 86400 secs, Renewal: 0 secs, Rebind: 0 secs
00:39:07: Next timer fires after: 00:00:01
00:39:07: Retry count: 1 Client-ID: cisco-0009.e899.0de0-Fa0/0
00:39:07: DHCP: SRequestInterface FastEthernet0/0 assigned DHCP address 10.136.27.86, mask 255.255.252.0
- Server ID option: 172.19.97.16
00:39:07: DHCP: SRequest- Requested IP addr option: 10.136.27.86
00:39:07: DHCP: SRequest placed lease len option: 86400
00:39:07: DHCP: SRequest: 324 bytes
00:39:07: DHCP: SRequest: 324 bytes
00:39:07: B'cast on FastEthernet0/0 interface from 0.0.0.0
00:39:07: DHCP: Received a BOOTREP pkt
00:39:07: DHCP: Scan: Message type: DHCP Ack
00:39:07: DHCP: Scan: Server ID Option: 172.19.97.16 = AC136110
00:39:07: DHCP: Scan: Lease Time: 86400
00:39:07: DHCP: Scan: Subnet Address Option: 255.255.252.0
00:39:07: DHCP: Scan: DNS Name Server Option: 68.105.28.12, 68.105.29.12, &68.105.28.11&
00:39:07: DHCP: Scan: Domain Name: sd.cox.net
00:39:07: DHCP: Scan: Router Option: 10.136.24.1
00:39:07: DHCP: rcvd pkt source: 10.136.16.1, destination: 255.255.255.255
00:39:07: UDP sport: 43, dport: 44, length: 318
00:39:07: DHCP op: 2, htype: 1, hlen: 6, hops: 1
00:39:07: DHCP server identifier: 172.19.97.16
00:39:07: xid: 976, secs: 0, flags: 8000
00:39:07: client: 0.0.0.0, your: 10.136.27.86
00:39:07: srvr: 172.19.97.16, gw: 10.136.16.1
00:39:07: options block length: 70

00:39:07: DHCP Ack Message
00:39:07: DHCP: Lease Seconds: 86400
00:39:07: DHCP: Server ID Option: 172.19.97.16
00:39:10: DHCP Proxy Client Pooling: ***Allocated IP address: 10.136.27.86
00:39:10: Allocated IP address = 10.136.27.86 255.255.252.0


It said it pulled the ip from 172.19.97.16 which is fine but then said it was assigned 10.136.27.86 which is not right. Anyone have any idea what is going on? my pix connects just fine.

here is a debug all if it will help:

http://tinyurl.com/cqo83t

also note, that is not a private IP from my modem. The modem will assign a 192.168.1.100 ip to a device if it has not yet received a public IP from the ISP. I've seen the PIX get that IP right after a reset, but it soon changes to the public 68.x.x.x IP cox provides.

My config was a default blank config plus this:
!
interface Ethernet0/0
ip address dhcp
no cdp enable
!

thanks in advance.

 

[brianinms]

If you are swapping devices connected to your modem you need to unplug your modem for ten minutes in between devices

 

[kutsunee]

I had powered the modem off for 30 seconds between switching devices. (worked between the pix and my laptop) are you sure it is 10 minutes and not 30 seconds?

Thanks for the response.

 

[brianinms]

The time depends on the configuration of the ISP's infrastructure. I say 10 min as the mac is clearly flushed from their system by then. Most providers its a 5 min time out.

 

[kutsunee]

I turned the modem off for 10 minutes and then booted it without anything plugged in. Connected my 2621 and the same thing happened. *confused* doesn't seem like that is the problem though. Any other ideas?

 

[ryezak]

Can you get a Public IP dynamically onto your laptop?or do you get assigned a private one on it as well? Sometimes I temp change my mac to the same as the one that is registered with the ISP.

You could call the ISP and get them to clear there arp cache and re-register a the new one on the 2600.
Do you have to register your mac with the isp? I know we have to register in a private subnet before getting assigned the public one. Some Providers do this.