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Re: Question on binding DHCP to an interface (by ifname, not IP/netmask

To: Ted Lemon <mellon@xxxxxxx>, netdev <netdev@xxxxxxxxxxx>
Subject: Re: Question on binding DHCP to an interface (by ifname, not IP/netmask).
From: Ben Greear <greearb@xxxxxxxx>
Date: Tue, 18 Jan 2000 18:15:55 -0700
Organization: AG Communication Systems
Posted-date: Tue, 18 Jan 2000 18:15:09 -0700 (MST)
References: <200001180137.UAA06520@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Reply-to: greearb@xxxxxxxx
Sender: owner-netdev@xxxxxxxxxxx
Ted Lemon wrote:

> > I'll let you know how it goes...
>
> Okay!   Should work fine - this is a very frequently used feature.
> You might pick up a copy of the DHCP handbook if you want a good
> feature tour...   :')
>
>                                _MelloN_

If I can get this demo working, I'll get mgt to spring for a handbook :)

Well, it's not working, and it *looks* like DHCP is to blame, but it could
still easily be something on my end.  I'm including a bunch of information here
in the hopes that it might make it easy for you to see the root of my problem.

Note that I'm using VLAN interfaces, which, at least untill this point, looked
exactly like ethernet interfaces to every program I've tried to run.  If you are
interested in the vlan patches, see my web page at:
http://scry.wanfear.com/~greear/vlan.html

I forgot to print the route table, but I have host routes to all the 130.X 
devices
hanging off of the 10.x vlan devices.  If the routes would be useful, I'll 
happly
go get a capture of them...

Thanks a heap!!

--Ben


Here is the output:

*************************************************************************************
I flushed firewall rules:  ipchains -F  before I did this, just to make
sure it wasn't the firewall.



[root@linserv /root]# ifconfig -a
dummy     Link encap:Ethernet  HWaddr 00:00:00:00:00:00
          BROADCAST NOARP  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0

eth0      Link encap:Ethernet  HWaddr 00:60:97:29:6F:B2
          inet addr:130.131.190.238  Bcast:130.131.190.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:611 errors:0 dropped:0 overruns:0 frame:0
          TX packets:64 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          Interrupt:9 Base address:0xff80

eth1      Link encap:Ethernet  HWaddr 00:60:97:3C:E6:09
          inet addr:192.168.101.1  Bcast:192.168.101.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:46 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100
          Interrupt:5 Base address:0xff40

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:3924  Metric:1
          RX packets:36 errors:0 dropped:0 overruns:0 frame:0
          TX packets:36 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0

vlan0000  Link encap:Ethernet  HWaddr 00:60:97:3C:E6:09
          inet addr:10.1.0.1  Bcast:10.255.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0

vlan0001  Link encap:Ethernet  HWaddr 00:60:97:3C:E6:09
          inet addr:10.1.0.2  Bcast:10.255.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:46 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0

vlan0002  Link encap:Ethernet  HWaddr 00:60:97:3C:E6:09
          inet addr:10.1.0.3  Bcast:10.255.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0

******************************************
[ Some notes on the dhcpd.conf file:
I want to give, in these cases, exactly one IP out for each VLAN interface.
That IP has nothing to do with the interface, as far as IP/Mask is concerned.

For example, on vlan0001 (VID 21), I want to serve only the ip address:  
130.131.190.212
******************************************

[root@linserv /root]# more /etc/dhcpd.conf

default-lease-time 6000000;
max-lease-time 12000000;
option routers 130.131.190.254;
option domain-name "agcs.com";
option domain-name-servers 130.131.190.254;

 shared-network vlan0000_20 {
   subnet 10.1.0.1 netmask 255.255.255.255 {
   }
   subnet 130.131.190.211 netmask 255.255.255.255 {
      range 130.131.190.211 130.131.190.211;
   }
 }

 shared-network vlan0001_21 {
   subnet 10.1.0.2 netmask 255.255.255.255 {
   }
   subnet 130.131.190.212 netmask 255.255.255.255 {
      range 130.131.190.212 130.131.190.212;
   }
 }

 shared-network vlan0002_22 {
   subnet 10.1.0.3 netmask 255.255.255.255 {
   }
   subnet 130.131.190.213 netmask 255.255.255.255 {
      range 130.131.190.213 130.131.190.213;
   }
 }

 subnet 130.131.190.238 netmask 255.255.255.255 { }
 subnet 192.168.101.1 netmask 255.255.255.255 { }


# End of customer DHCPd entries.



[from /var/log/messages, when dhcpd is started (and while the tcpdump, below, 
is running)
 Note that I see absolutely zero messages from DHCP, as though it isn't even 
getting
 the requests.]

Jan 18 17:48:44 linserv dhcpd: Internet Software Consortium DHCP Server 2.0
Jan 18 17:48:44 linserv dhcpd: Copyright 1995, 1996, 1997, 1998, 1999 The 
Internet Software Consortium.
Jan 18 17:48:44 linserv dhcpd: All rights reserved.
Jan 18 17:48:44 linserv dhcpd:
Jan 18 17:48:44 linserv dhcpd: Please contribute if you find this software 
useful.
Jan 18 17:48:44 linserv dhcpd: For info, please visit 
http://www.isc.org/dhcp-contrib.html
Jan 18 17:48:44 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Internet Software Consortium DHCP Server 2.0
Jan 18 17:48:45 linserv dhcpd: Copyright 1995, 1996, 1997, 1998, 1999 The 
Internet Software Consortium.
Jan 18 17:48:45 linserv dhcpd: All rights reserved.
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Please contribute if you find this software 
useful.
Jan 18 17:48:45 linserv dhcpd: For info, please visit 
http://www.isc.org/dhcp-contrib.html
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/vlan0002/00:60:97:3c:e6:09/vlan0002_22
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/vlan0002/00:60:97:3c:e6:09/vlan0002_22
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/vlan0002/00:60:97:3c:e6:09/vlan0002_22
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/vlan0002/00:60:97:3c:e6:09/vlan0002_22
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/vlan0001/00:60:97:3c:e6:09/vlan0001_21
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/vlan0001/00:60:97:3c:e6:09/vlan0001_21
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/vlan0001/00:60:97:3c:e6:09/vlan0001_21
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/vlan0001/00:60:97:3c:e6:09/vlan0001_21
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/vlan0000/00:60:97:3c:e6:09/vlan0000_20
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/vlan0000/00:60:97:3c:e6:09/vlan0000_20
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/vlan0000/00:60:97:3c:e6:09/vlan0000_20
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/vlan0000/00:60:97:3c:e6:09/vlan0000_20
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/eth1/00:60:97:3c:e6:09/192.168.101.1
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/eth1/00:60:97:3c:e6:09/192.168.101.1
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/eth1/00:60:97:3c:e6:09/192.168.101.1
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/eth1/00:60:97:3c:e6:09/192.168.101.1
Jan 18 17:48:45 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/eth0/00:60:97:29:6f:b2/130.131.190.238
Jan 18 17:48:45 linserv dhcpd: Listening on 
LPF/eth0/00:60:97:29:6f:b2/130.131.190.238
Jan 18 17:48:46 linserv dhcpd:
Jan 18 17:48:45 linserv dhcpd: Sending on   
LPF/eth0/00:60:97:29:6f:b2/130.131.190.238
Jan 18 17:48:46 linserv dhcpd: Sending on   
LPF/eth0/00:60:97:29:6f:b2/130.131.190.238
Jan 18 17:48:46 linserv dhcpd:
Jan 18 17:48:46 linserv dhcpd: Sending on   Socket/fallback/fallback-net
Jan 18 17:48:46 linserv dhcpd: Sending on   Socket/fallback/fallback-net
Jan 18 17:48:46 linserv dhcpd:
Jan 18 17:48:46 linserv dhcpd: dhcpd startup succeeded




[bootp (dhcp) requests coming in on vlan0001]


[root@linserv /root]# tcpdump -n -i vlan0001
Kernel filter, protocol ALL, datagram packet socket
tcpdump: listening on vlan0001
17:46:03.890910 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:07.885369 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:14.883378 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:27.881390 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:33.879998 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:33.887310 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:33.891304 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:33.895329 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:33.902715 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:33.906730 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]
17:46:33.910755 B 0.0.0.0.bootpc > 255.255.255.255.bootps: xid:0x653c6df3 
[|bootp]


--
Ben Greear        greearb@xxxxxxxx   Pager: 202-2717
(623) 581 4980    "More weight!" -- _The Crucible._
http://hydrogen:8080/home/greearb/public_html/index.html




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