[Pkg-utopia-maintainers] Bug#855180: Networkmanager sends bad DHCP-requests

Wed Feb 15 07:17:11 UTC 2017

Package: network-manager
Version: 1.6.0-1

When i am using the default NetowkManager.conf which looks like:

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false

NM sends bad DHCP-Requests. Here is an example dump:

% sudo dhcpdump -i enp0s31f6
   TIME: 2017-02-15 07:53:30.353
     IP: 0.0.0.0 (18:db:f2:4f:0:59) > 255.255.255.255 (ff:ff:ff:ff:ff:ff)
     OP: 1 (BOOTPREQUEST)
  HTYPE: 1 (Ethernet)
   HLEN: 6
   HOPS: 0
    XID: d404c631
   SECS: 0
  FLAGS: 0
CIADDR: 0.0.0.0
YIADDR: 0.0.0.0
SIADDR: 0.0.0.0
GIADDR: 0.0.0.0
CHADDR: 18:db:f2:4f:00:59:00:00:00:00:00:00:00:00:00:00
  SNAME: .
  FNAME: .
OPTION:  53 (  1) DHCP message type         3 (DHCPREQUEST)
OPTION:  50 (  4) Request IP address        192.168.168.107
OPTION:  12 ( 12) Host name                 mschirmacher
OPTION:  55 ( 23) Parameter Request List      1 (Subnet mask)
					     28 (Broadcast address)
					      2 (Time offset)
					      3 (Routers)
					     15 (Domainname)
					      6 (DNS server)
					     12 (Host name)
					      1 (Subnet mask)
					     28 (Broadcast address)
					      2 (Time offset)
					      3 (Routers)
					     15 (Domainname)
					      6 (DNS server)
					    119 (Domain Search)
					     12 (Host name)
					     44 (NetBIOS name server)
					     47 (NetBIOS scope)
					     26 (Interface MTU)
					    121 (Classless Static Route)
					     42 (NTP servers)
					    249 (MSFT - Classless route)
					     33 (Static route)
					    252 (MSFT - WinSock Proxy Auto Detect)

---------------------------------------------------------------------------

   TIME: 2017-02-15 07:53:30.457
     IP: 192.168.168.7 (5c:f3:fc:e6:20:7c) > 255.255.255.255 
(ff:ff:ff:ff:ff:ff)
     OP: 2 (BOOTPREPLY)
  HTYPE: 1 (Ethernet)
   HLEN: 6
   HOPS: 0
    XID: d404c631
   SECS: 0
  FLAGS: 0
CIADDR: 0.0.0.0
YIADDR: 192.168.168.107
SIADDR: 0.0.0.0
GIADDR: 0.0.0.0
CHADDR: 18:db:f2:4f:00:59:00:00:00:00:00:00:00:00:00:00
  SNAME: .
  FNAME: .
OPTION:  53 (  1) DHCP message type         5 (DHCPACK)
OPTION:  58 (  4) T1                        86400 (24h)
OPTION:  59 (  4) T2                        151200 (1d18h)
OPTION:  51 (  4) IP address leasetime      172800 (2d)
OPTION:  54 (  4) Server identifier         192.168.168.7
OPTION:   1 (  4) Subnet mask               255.255.255.0
OPTION:   3 (  4) Routers                   192.168.168.6
OPTION:  15 ( 19) Domainname                intern.our.domain
OPTION:   6 ( 12) DNS server                
192.168.168.7,172.29.0.8,172.29.0.9
OPTION:   3 (  4) Routers                   192.168.168.6
OPTION:  15 ( 19) Domainname                intern.our.domain
OPTION:   6 ( 12) DNS server                
192.168.168.7,172.29.0.8,172.29.0.9
OPTION:  42 ( 16) NTP servers               
129.250.35.251,85.114.132.52,5.9.39.18,193.175.73.151

As you can see most options, especially Option 15 appears twice in the 
request as well as in the response. Comsequently the genererates 
/etc/resolv.conf would look like:

% cat /etc/resolv.conf
# Generated by NetworkManager
search intern.our.domainintern.our.domain
nameserver 192.168.168.7
nameserver 172.29.0.8
nameserver 172.29.0.9

Note the bad line "search intern.our.domainintern.our.domain" where NM 
concatenated the domain names from the two Option 15 responses.

When i add the line dhcp=internal to the [main] section of the 
NetworkManager.conf the DHCP request sent will not contain duplicate 
option requests hence the answer will be correct, too, resulting in a 
valid resolv.conf

FWIW here some more installed packages that might be relevant:

ii  network-manager                       1.6.0-1
ii  network-manager-gnome                 1.4.4-1
ii  network-manager-openvpn               1.2.8-2
ii  network-manager-openvpn-gnome         1.2.8-2
ii  network-manager-vpnc                  1.2.4-4
ii  network-manager-vpnc-gnome            1.2.4-4
ii  isc-dhcp-client                       4.3.5-3
ii  isc-dhcp-common                       4.3.5-3

Thank you