[Dnsmasq-discuss] Weird Routing/FW/dnsmasq problem
Dan Shechter
DanS at GoNetworks.com
Sun Oct 30 21:35:12 GMT 2005
Hi,
This isn't really a dnsmasq problem, but a "routing" problem,
I'm mailing this here hoping that someone overcame this before...
I'm trying to get dnsmasq to respond with "DHCPNAK" commands while in
dhcp-authorative mode.
The "catch", so to speak, is that the clients are roaming in from
different
networks. And sometimes when they "come-in" to the dnsmasq managed
network, they generate packets which are local broadcast packets from
their old source ip address to 255.255.255.255.
For example, clients generate DHCP REQUEST packets from:
10.100.4.134 -> 255.255.255.255
while dnsmasq runs on a machine where the interface receiving the
broadcast packet is configured as "192.168.101.200".
I cannot seem to successfully make dnsmasq "respond" to these packets.
dnsmasq remains sleeping (verified with strace) while these DHCP REQUEST
packets are generated.
I've attached two ethereal dump files, one is a plain packet dump, one
is a
Detailed one:
The client try the same DHCP request 3 times (packets 418-420), and
gives up after 40 seconds, doing a DHCP DISCOVER (packet 421) with
source address "0.0.0.0" which succeeds.
Any help will be GREATLY appreciated!
----------
Dan Shechter <dans *at* gonetworks.com>
-------------- next part --------------
No. Time Source Destination Protocol Info
418 5990.757624 10.100.4.134 255.255.255.255 DHCP DHCP Request - Transaction ID 0xbb259ff8
Frame 418 (356 bytes on wire, 356 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 10.100.4.134 (10.100.4.134), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
No. Time Source Destination Protocol Info
419 5995.762079 10.100.4.134 255.255.255.255 DHCP DHCP Request - Transaction ID 0xbb259ff8
Frame 419 (356 bytes on wire, 356 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 10.100.4.134 (10.100.4.134), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
No. Time Source Destination Protocol Info
420 6002.762150 10.100.4.134 255.255.255.255 DHCP DHCP Request - Transaction ID 0xbb259ff8
Frame 420 (356 bytes on wire, 356 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 10.100.4.134 (10.100.4.134), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
No. Time Source Destination Protocol Info
421 6022.310948 0.0.0.0 255.255.255.255 DHCP DHCP Discover - Transaction ID 0x8f93ada4
Frame 421 (344 bytes on wire, 344 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
No. Time Source Destination Protocol Info
422 6025.061742 192.168.101.200 255.255.255.255 DHCP DHCP Offer - Transaction ID 0x8f93ada4
Frame 422 (344 bytes on wire, 344 bytes captured)
Ethernet II, Src: TyanComp_30:e9:cf (00:e0:81:30:e9:cf), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 192.168.101.200 (192.168.101.200), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootps (67), Dst Port: bootpc (68)
Bootstrap Protocol
No. Time Source Destination Protocol Info
423 6025.062147 0.0.0.0 255.255.255.255 DHCP DHCP Request - Transaction ID 0x8f93ada4
Frame 423 (368 bytes on wire, 368 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
No. Time Source Destination Protocol Info
424 6025.066490 192.168.101.200 255.255.255.255 DHCP DHCP ACK - Transaction ID 0x8f93ada4
Frame 424 (379 bytes on wire, 379 bytes captured)
Ethernet II, Src: TyanComp_30:e9:cf (00:e0:81:30:e9:cf), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Internet Protocol, Src: 192.168.101.200 (192.168.101.200), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootps (67), Dst Port: bootpc (68)
Bootstrap Protocol
-------------- next part --------------
No. Time Source Destination Protocol Info
418 5990.757624 10.100.4.134 255.255.255.255 DHCP DHCP Request - Transaction ID 0xbb259ff8
Frame 418 (356 bytes on wire, 356 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Source: Dell_3c:85:80 (00:11:43:3c:85:80)
Type: IP (0x0800)
Internet Protocol, Src: 10.100.4.134 (10.100.4.134), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xbb259ff8
Seconds elapsed: 0
Bootp flags: 0x0000 (Unicast)
Client IP address: 10.100.4.134 (10.100.4.134)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Dell_3c:85:80 (00:11:43:3c:85:80)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP Request
Option 61: Client identifier
Option 12: Host Name = "qa-05-dell-d505"
Option 81: FQDN
Option 60: Vendor class identifier = "MSFT 5.0"
Option 55: Parameter Request List
End Option
No. Time Source Destination Protocol Info
419 5995.762079 10.100.4.134 255.255.255.255 DHCP DHCP Request - Transaction ID 0xbb259ff8
Frame 419 (356 bytes on wire, 356 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Source: Dell_3c:85:80 (00:11:43:3c:85:80)
Type: IP (0x0800)
Internet Protocol, Src: 10.100.4.134 (10.100.4.134), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xbb259ff8
Seconds elapsed: 1280
Bootp flags: 0x0000 (Unicast)
Client IP address: 10.100.4.134 (10.100.4.134)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Dell_3c:85:80 (00:11:43:3c:85:80)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP Request
Option 61: Client identifier
Option 12: Host Name = "qa-05-dell-d505"
Option 81: FQDN
Option 60: Vendor class identifier = "MSFT 5.0"
Option 55: Parameter Request List
End Option
No. Time Source Destination Protocol Info
420 6002.762150 10.100.4.134 255.255.255.255 DHCP DHCP Request - Transaction ID 0xbb259ff8
Frame 420 (356 bytes on wire, 356 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Source: Dell_3c:85:80 (00:11:43:3c:85:80)
Type: IP (0x0800)
Internet Protocol, Src: 10.100.4.134 (10.100.4.134), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0xbb259ff8
Seconds elapsed: 3072
Bootp flags: 0x0000 (Unicast)
Client IP address: 10.100.4.134 (10.100.4.134)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Dell_3c:85:80 (00:11:43:3c:85:80)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP Request
Option 61: Client identifier
Option 12: Host Name = "qa-05-dell-d505"
Option 81: FQDN
Option 60: Vendor class identifier = "MSFT 5.0"
Option 55: Parameter Request List
End Option
No. Time Source Destination Protocol Info
421 6022.310948 0.0.0.0 255.255.255.255 DHCP DHCP Discover - Transaction ID 0x8f93ada4
Frame 421 (344 bytes on wire, 344 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Source: Dell_3c:85:80 (00:11:43:3c:85:80)
Type: IP (0x0800)
Internet Protocol, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0x8f93ada4
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Dell_3c:85:80 (00:11:43:3c:85:80)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP Discover
Option 116: DHCP Auto-Configuration (1 bytes)
Option 61: Client identifier
Option 50: Requested IP Address = 10.100.4.134
Option 12: Host Name = "qa-05-dell-d505"
Option 60: Vendor class identifier = "MSFT 5.0"
Option 55: Parameter Request List
End Option
No. Time Source Destination Protocol Info
422 6025.061742 192.168.101.200 255.255.255.255 DHCP DHCP Offer - Transaction ID 0x8f93ada4
Frame 422 (344 bytes on wire, 344 bytes captured)
Ethernet II, Src: TyanComp_30:e9:cf (00:e0:81:30:e9:cf), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Source: TyanComp_30:e9:cf (00:e0:81:30:e9:cf)
Type: IP (0x0800)
Internet Protocol, Src: 192.168.101.200 (192.168.101.200), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootps (67), Dst Port: bootpc (68)
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0x8f93ada4
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 192.168.101.66 (192.168.101.66)
Next server IP address: 192.168.101.200 (192.168.101.200)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Dell_3c:85:80 (00:11:43:3c:85:80)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP Offer
Option 54: Server Identifier = 192.168.101.200
Option 51: IP Address Lease Time = 2 minutes
Option 58: Renewal Time Value = 1 minute
Option 59: Rebinding Time Value = 1 minute, 45 seconds
Option 1: Subnet Mask = 255.255.255.0
Option 3: Router = 192.168.101.200
Option 6: Domain Name Server = 192.168.101.200
Option 15: Domain Name = "gonetworks.com"
End Option
No. Time Source Destination Protocol Info
423 6025.062147 0.0.0.0 255.255.255.255 DHCP DHCP Request - Transaction ID 0x8f93ada4
Frame 423 (368 bytes on wire, 368 bytes captured)
Ethernet II, Src: Dell_3c:85:80 (00:11:43:3c:85:80), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Source: Dell_3c:85:80 (00:11:43:3c:85:80)
Type: IP (0x0800)
Internet Protocol, Src: 0.0.0.0 (0.0.0.0), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootpc (68), Dst Port: bootps (67)
Bootstrap Protocol
Message type: Boot Request (1)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0x8f93ada4
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 0.0.0.0 (0.0.0.0)
Next server IP address: 0.0.0.0 (0.0.0.0)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Dell_3c:85:80 (00:11:43:3c:85:80)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP Request
Option 61: Client identifier
Option 50: Requested IP Address = 192.168.101.66
Option 54: Server Identifier = 192.168.101.200
Option 12: Host Name = "qa-05-dell-d505"
Option 81: FQDN
Option 60: Vendor class identifier = "MSFT 5.0"
Option 55: Parameter Request List
End Option
No. Time Source Destination Protocol Info
424 6025.066490 192.168.101.200 255.255.255.255 DHCP DHCP ACK - Transaction ID 0x8f93ada4
Frame 424 (379 bytes on wire, 379 bytes captured)
Ethernet II, Src: TyanComp_30:e9:cf (00:e0:81:30:e9:cf), Dst: Broadcast (ff:ff:ff:ff:ff:ff)
Destination: Broadcast (ff:ff:ff:ff:ff:ff)
Source: TyanComp_30:e9:cf (00:e0:81:30:e9:cf)
Type: IP (0x0800)
Internet Protocol, Src: 192.168.101.200 (192.168.101.200), Dst: 255.255.255.255 (255.255.255.255)
User Datagram Protocol, Src Port: bootps (67), Dst Port: bootpc (68)
Bootstrap Protocol
Message type: Boot Reply (2)
Hardware type: Ethernet
Hardware address length: 6
Hops: 0
Transaction ID: 0x8f93ada4
Seconds elapsed: 0
Bootp flags: 0x8000 (Broadcast)
Client IP address: 0.0.0.0 (0.0.0.0)
Your (client) IP address: 192.168.101.66 (192.168.101.66)
Next server IP address: 192.168.101.200 (192.168.101.200)
Relay agent IP address: 0.0.0.0 (0.0.0.0)
Client MAC address: Dell_3c:85:80 (00:11:43:3c:85:80)
Server host name not given
Boot file name not given
Magic cookie: (OK)
Option 53: DHCP Message Type = DHCP ACK
Option 54: Server Identifier = 192.168.101.200
Option 51: IP Address Lease Time = 2 minutes
Option 58: Renewal Time Value = 1 minute
Option 59: Rebinding Time Value = 1 minute, 45 seconds
Option 1: Subnet Mask = 255.255.255.0
Option 3: Router = 192.168.101.200
Option 6: Domain Name Server = 192.168.101.200
Option 15: Domain Name = "gonetworks.com"
Option 81: FQDN
End Option
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