From: Brian McGahan (bmcgahan@internetworkexpert.com)
Date: Fri Nov 05 2004 - 19:16:04 GMT-3
Andrew,
Have you tried this config? :)
Brian McGahan, CCIE #8593
bmcgahan@internetworkexpert.com
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> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
Of
> Edwards, Andrew M
> Sent: Friday, November 05, 2004 3:14 PM
> To: ccie2be; ccielab@groupstudy.com
> Subject: RE: dhcp and address negotiation over an isdn link
>
> Well, I guess its kind of caveat emptor...
>
> But, I think between the two of us we've nailed this one.
>
> With R4 being negotiate, R5 has to be setup for both ip dhcp-server
and
> ip dhcp-proxy.
>
> If R4 were an ip add dhcp-client though... R5 would need
helper-address.
>
> Of course, its blind leading the blind here... But I do know a bit
about
> DHCP. 8)
>
>
> -----Original Message-----
> From: ccie2be [mailto:ccie2be@nyc.rr.com]
> Sent: Friday, November 05, 2004 12:16 PM
> To: Edwards, Andrew M; ccielab@groupstudy.com
> Subject: Re: dhcp and address negotiation over an isdn link
>
>
> Hi Andrew,
>
> I was thinking about what you said below about using the command, ip
> address-pool dhcp-proxy-client. And, it made me wonder if I was
> thinking about this all wrong.
>
> Initially, I was thinking that once the link between R4 and R5 came
up,
> R4 because it has ip address negotiated configured on it becomes a
dhcp
> client and therefore would send out a dhcp request.
>
> But, maybe this is wrong because R4 is connecting to R5 via PPP and
> using PPP to negotiate an ip address. In other words, R4 isn't a
really
> dhcp client so it doesn't send out a dhcp request for an address.
>
> But, now, looking at R5's configuration. It has the interface
command,
> peer default ip address dhcp, on it's Dialer interface which means it
> should use dhcp to get and assign an ip address to R4 when it gets a
> dhcp request from R4. But, because R4 isn't really (or rather R4
> doesn't consider itself) a dhcp client, R4 never sends a dhcp request.
>
> Therefore, for R5 to get an ip address for R4, it must send a dhcp
> request on R4's behalf to the dhcp server and that's why the global
> command, ip address-pool dhcp-proxy-client, is needed.
>
> Realize that I'm completely making this up, but it seems plausible.
Am
> I getting warm?
>
> Thanks, Tim
> ----- Original Message -----
> From: "Edwards, Andrew M" <andrew.m.edwards@boeing.com>
> To: "ccie2be" <ccie2be@nyc.rr.com>; <ccielab@groupstudy.com>
> Sent: Friday, November 05, 2004 1:54 PM
> Subject: RE: IEWB lab 13 dhcp & isdn task 4.3 and task 12.1
>
>
> My thoughts....
>
> On R5, you need ip helper-address to R1.
>
> R5 is connecting to R4 on the callback but the DHCP lease is not being
> negotiated. R5 see's the R4 request but it can't do anything with
it...
>
> So, get R5 to encapsulate (unicast) and forward the local link
broadcast
> from R4 for a DHCP Lease Request. Once you see NCP on the BRI link
> negotiate the Network Control Protocol address received from R1 you
will
> get connectivity at layer 3 between r4 and r5.
>
> Alternatively, if you want to specify the IP address of the DHCP
server,
> you will need to use the global ip address-pool dhcp-proxy-client
> command to specify that R5 should proxy DHCP requests on behalf of
> locally connected clients. Two ways to do the same thing.... One
being
> more efficient (I think the later).
>
> HTH,
>
> andy
>
> -----Original Message-----
> From: ccie2be [mailto:ccie2be@nyc.rr.com]
> Sent: Friday, November 05, 2004 6:57 AM
> To: Group Study
> Subject: Fw: IEWB lab 13 dhcp & isdn task 4.3 and task 12.1
>
>
> Hey guys,
>
> In the isdn portion of this task, I needed to configure dialer
profiles
> on both R4 and R5, have R5 call R4 and then make R4 hangup and
callback
> R5. I got this part to work. To confirm that this was working I
used,
> isdn test call int bri 0/0 5272034 and enabled debug dialer on R4.
When
> I reviewed the debug logs, I could see the call from R5 connect, then
> disconnect and then R4 callback R5.
>
>
> However, I also needed to configure R4 to get it's dialer's interface
ip
> address from a dhcp server directly connected to R5.
>
> I also enabled debug dhcp on R4 and R5, but I can't tell from the
debug
> out what's really going on. So, I don't know if R4 ever really got an
ip
> address.
>
> I've configured R4 and R5 as shown is the SG, but the dhcp part
doesn't
> seem to working, although I'm not 100% sure. Once the link was up
after
> R4 called back R5, I did several pings but those never were
successful.
>
> I was struggling with this for hours but never got pings to work
across
> the isdn link, so I'm hoping someone can help me understand what's
going
> on.
>
> Here's some output from deb dhcp on R5:
>
> *Mar 1 07:08:42.478: DHCP Lease server: 0.0.0.0, state: 1
Selecting
> *Mar 1 07:08:42.478: DHCP transaction id: FCC10C
> *Mar 1 07:08:42.478: Lease: 0 secs, Renewal: 0 secs, Rebind: 0
> secs
> *Mar 1 07:08:42.478: Next timer fires after: 00:00:03
> *Mar 1 07:08:42.478: Retry count: 2 Client-ID:
> cisco-139.3.45.5-BRI0/0:1
> *Mar 1 07:08:42.478: DHCP: SDiscover: sending 285 byte length DHCP
> packet *Mar 1 07:08:42.478: DHCP: SDiscover 285 bytes *Mar 1
> 07:08:53.078: DHCP: QScan: Purging entry *Mar 1 07:08:53.078: DHCP:
> deleting entry 622AE8CC 0.0.0.0 from list *Mar 1 07:08:53.078: Temp
IP
> addr: 0.0.0.0 for peer on Interface: unknown *Mar 1 07:08:53.078:
Temp
> sub net mask: 0.0.0.0
> *Mar 1 07:08:53.078: DHCP Lease server: 0.0.0.0, state: 8 Purging
> *Mar 1 07:08:53.078: DHCP transaction id: FCC107
> *Mar 1 07:08:53.078: Lease: 0 secs, Renewal: 0 secs, Rebind: 0
> secs
> *Mar 1 07:08:53.078: No timer running
> *Mar 1 07:08:53.078: Retry count: 0 Client-ID:
> *Mar 1 07:08:57.178: DHCP: QScan: Purging entry
> *Mar 1 07:08:57.178: DHCP: deleting entry 629D70C0 0.0.0.0 from list
> *Mar 1 07:08:57.178: Temp IP addr: 0.0.0.0 for peer on Interface:
> unknown *Mar 1 07:08:57.178: Temp sub net mask: 0.0.0.0
> *Mar 1 07:08:57.178: DHCP Lease server: 0.0.0.0, state: 8 Purging
> *Mar 1 07:08:57.178: DHCP transaction id: FCC108
> *Mar 1 07:08:57.178: Lease: 0 secs, Renewal: 0 secs, Rebind: 0
> secs
> *Mar 1 07:08:57.178: No timer running
> *Mar 1 07:08:57.178: Retry count: 0 Client-ID:
> *Mar 1 07:09:01.278: DHCP: QScan: Purging entry
> *Mar 1 07:09:01.278: DHCP: deleting entry 622AE168 0.0.0.0 from list
> *Mar 1 07:09:01.278: Temp IP addr: 0.0.0.0 for peer on Interface:
> unknown *Mar 1 07:09:01.278: Temp sub net mask: 0.0.0.0
> *Mar 1 07:09:01.278: DHCP Lease server: 0.0.0.0, state: 8 Purging
> *Mar 1 07:09:01.278: DHCP transaction id: FCC109
> *Mar 1 07:09:01.278: Lease: 0 secs, Renewal: 0 secs, Rebind: 0
> secs
> *Mar 1 07:09:01.278: No timer running
> *Mar 1 07:09:01.278: Retry count: 0 Client-ID:
> *Mar 1 07:09:05.378: DHCP: QScan: Purging entry
> *Mar 1 07:09:05.378: DHCP: deleting entry 622A94C8 0.0.0.0 from list
> *Mar 1 07:09:05.378: Temp IP addr: 0.0.0.0 for peer on Interface:
> unknown *Mar 1 07:09:05.378: Temp sub net mask: 0.0.0.0
> *Mar 1 07:09:05.378: DHCP Lease server: 0.0.0.0, state: 8 Purging
> *Mar 1 07:09:05.378: DHCP transaction id: FCC10A
> *Mar 1 07:09:05.378: Lease: 0 secs, Renewal: 0 secs, Rebind: 0
> secs
> *Mar 1 07:09:05.378: No timer running
> *Mar 1 07:09:05.378: No timer running
> *Mar 1 07:09:09.478: DHCP: QScan: Purging entry
> *Mar 1 07:09:09.478: DHCP: deleting entry 629D34B0 0.0.0.0 from list
> *Mar 1 07:09:09.478: Temp IP addr: 0.0.0.0 for peer on Interface:
> unknown *Mar 1 07:09:09.478: Temp sub net mask: 0.0.0.0
> *Mar 1 07:09:09.478: DHCP Lease server: 0.0.0.0, state: 8 Purging
> *Mar 1 07:09:09.478: DHCP transaction id: FCC10B
> *Mar 1 07:09:09.478: Lease: 0 secs, Renewal: 0 secs, Rebind: 0
> secs
> *Mar 1 07:09:09.478: No timer running
> *Mar 1 07:09:09.478: Retry count: 0 Client-ID:
> *Mar 1 07:09:13.578: DHCP: QScan: Purging entry
> *Mar 1 07:09:13.578: DHCP: deleting entry 629D3684 0.0.0.0 from list
> *Mar 1 07:09:13.578: Temp IP addr: 0.0.0.0 for peer on Interface:
> BRI0/0:1 *Mar 1 07:09:13.578: Temp sub net mask: 0.0.0.0
> *Mar 1 07:09:13.578: DHCP Lease server: 0.0.0.0, state: 8 Purging
> *Mar 1 07:09:13.578: DHCP transaction id: FCC10C
> *Mar 1 07:09:13.578: Lease: 0 secs, Renewal: 0 secs, Rebind: 0
> secs
> *Mar 1 07:09:13.578: No timer running
> *Mar 1 07:09:13.578: Retry count: 0 Client-ID:
> cisco-139.3.45.5-BRI0/0:1
> *Mar 1 07:10:18.866: %ISDN-6-DISCONNECT: Interface BRI0/0:1
> disconnected from 5272034 , call lasted 120 seconds *Mar 1
> 07:10:18.918: %LINK-3-UPDOWN: Interface BRI0/0:1, changed state to
down
> *Mar 1 07:10:18.922: %DIALER-6-UNBIND: Interface BR0/0:1 unbound from
> profile D i1
>
************************************************************************
> *****
> ********************
>
> I also did a deb dhcp on R1, the dhcp server, but got nothing at all.
>
> Here's R4's config. R4 is the dhcp client and is suppose to get an ip
> address assigned to it dialer interface.
>
>
> interface Dialer1
> ip address negotiated
> encapsulation ppp
> dialer pool 1
> dialer string 5272035
> dialer caller 5272035 callback
>
> Here's R5's config:
>
> ip dhcp-server 139.3.15.1
>
> interface Dialer1
> ip address 139.3.45.5 255.255.255.0
> encapsulation ppp
> dialer pool 1
> dialer string 5272034
> dialer-group 1
> peer default ip address dhcp
>
> Here's R1's config. R1 is the dhcp server.
>
> ip dhcp excluded-address 139.3.45.5 139.3.45.255
> ip dhcp excluded-address 139.3.45.0 139.3.45.3
> !
> ip dhcp pool FOR-R4
> network 139.3.45.0 255.255.255.0
>
> Here's the topology:
>
> R4 --- isdn ---- R5 --- f/r --- R1
>
> I'm not running any routing protocols, but R5 and R1 can ping each
> other.
>
> R5 can call R4. When it does, R4 takes the call, hangup, and calls R5
> back. But, once the call is connected, R4 and R5 still can't ping each
> other. A debug on R5 shows the pings are "unroutable". I don't know
> why since, of course, R4 and R5 are directly connected via the isdn
> link.
>
> Can anybody help me understand what's going on here with dhcp and the
> ping problem?
>
> Thanks for any insight.
>
> Tim
>
>
This archive was generated by hypermail 2.1.4 : Thu Dec 02 2004 - 06:57:39 GMT-3