Dotaz: 2 DHCPD v sieti

[nicco]

Ahoj,
mam takyto podivny Lab:
WindowsXP, na nom VMwarePlayer, v nom Centos(1) a v nom Xen domenu s dalsim Centosom(2)

VMPlayer(192.168.79.2) ma vlastny DHCPD a moze obsluzit Centos1 aj Centos2.
Ja som ale na Centos1 nastavil staticku IP(192.168.0.1) a nainstaloval som si tam vlastny DHCPD a chcem, aby Centos2 dostaval IPcku (192.168.0.254) z Centosu1, nie od VMPlayeru(192.168.79.136).

Mam v logu toto:
Jul 3 22:23:52 CentOS dhcpd: DHCPREQUEST for 192.168.79.136 from 00:16:3e:6f:99:86 via eth0: wrong network.
Jul 3 22:23:52 CentOS dhcpd: DHCPNAK on 192.168.79.136 to 00:16:3e:6f:99:86 via eth0

Ak vypnem network adapter vo VMPlayerovi a restartujem siet na Centos2, tak spravne nostanem IP z Centos1:

Jul 3 22:44:54 CentOS avahi-daemon[3132]: Interface eth0.IPv4 no longer relevant for mDNS.
Jul 3 22:44:54 CentOS avahi-daemon[3132]: Leaving mDNS multicast group on interface eth0.IPv4 with address 192.168.0.1.
Jul 3 22:44:54 CentOS avahi-daemon[3132]: Withdrawing address record for 192.168.0.1 on eth0.
Jul 3 22:44:54 CentOS dhcpd: receive_packet failed on eth0: Network is down
Jul 3 22:45:20 CentOS avahi-daemon[3132]: New relevant interface eth0.IPv4 for mDNS.
Jul 3 22:45:20 CentOS avahi-daemon[3132]: Joining mDNS multicast group on interface eth0.IPv4 with address 192.168.0.1.
Jul 3 22:45:20 CentOS avahi-daemon[3132]: Registering new address record for 192.168.0.1 on eth0.
Jul 3 22:45:55 CentOS dhcpd: DHCPREQUEST for 192.168.79.136 from 00:16:3e:6f:99:86 via eth0: wrong network.
Jul 3 22:45:55 CentOS dhcpd: DHCPNAK on 192.168.79.136 to 00:16:3e:6f:99:86 via eth0
Jul 3 22:46:28 CentOS kernel: e1000: peth0 NIC Link is Down
Jul 3 22:46:28 CentOS kernel: xenbr0: port 1(peth0) entering disabled state
Jul 3 22:46:37 CentOS dhcpd: DHCPREQUEST for 192.168.79.136 from 00:16:3e:6f:99:86 via eth0: wrong network.
Jul 3 22:46:37 CentOS dhcpd: DHCPNAK on 192.168.79.136 to 00:16:3e:6f:99:86 via eth0
Jul 3 22:46:37 CentOS dhcpd: DHCPDISCOVER from 00:16:3e:6f:99:86 via eth0
Jul 3 22:46:38 CentOS dhcpd: DHCPOFFER on 192.168.0.254 to 00:16:3e:6f:99:86 (XENtest2) via eth0
Jul 3 22:46:38 CentOS dhcpd: Unable to add forward map from XENtest2.mydomain.org to 192.168.0.254: connection refused
Jul 3 22:46:38 CentOS dhcpd: DHCPREQUEST for 192.168.0.254 (192.168.0.1) from 00:16:3e:6f:99:86 (XENtest2) via eth0
Jul 3 22:46:38 CentOS dhcpd: DHCPACK on 192.168.0.254 to 00:16:3e:6f:99:86 (XENtest2) via eth0


Preco to stale berie z VMPlayeru? A ako to urobit, bez toho, aby som nemusel vypinat network vo VMPayerovi?

Skusal som dhclient -r, ale nepomohlo.

Diky

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Odpovědi

[Jiří Veselský]

No systematické by bylo v VMplayeru vypnout DHCP, ale to teda nevím, jestli to jde.

Pak mě napadá v Centos1 přidat do iptables nějaké vhodné pravidlo, které bude blokovat provoz na UDP portech 67/68, tj. DHCP portech, a to na té síťové kartě která vede do VMplayeru. Takže dotaz od Centos2 (a/nebo odpověď od VMplayeru) tímdle pravidlem neprojde. Je ovšem otázka, jestli to bude fungovat, protože netuším, jako "nízko" visí Xen v systému, jestli jeho síťový provoz podléhá či nepodléhá filtraci iptablesů toho hostitelského OS.

[nicco]

Skusil som teda zablokovat DHCPD:

-A RH-Firewall-1-INPUT -p tcp -i eth0 --sport 67:68 --dport 67:68 -j DROP
-A RH-Firewall-1-INPUT -p udp -i eth0 --sport 67:68 --dport 67:68 -j DROP

ale nepomohlo to. Stale tam ma request na oba DHCPD:

DHCPREQUEST for 192.168.0.254 (192.168.0.1) a DHCPREQUEST for 192.168.79.136 (192.168.79.254)

Jul 4 10:26:46 CentOS dhcpd: DHCPDISCOVER from 00:16:3e:6f:99:86 via eth0
Jul 4 10:26:47 CentOS dhcpd: DHCPOFFER on 192.168.0.254 to 00:16:3e:6f:99:86 (XENtest2) via eth0
Jul 4 10:26:48 CentOS dhcpd: Unable to add forward map from XENtest2.mydomain.org to 192.168.0.254: timed out
Jul 4 10:26:48 CentOS dhcpd: DHCPREQUEST for 192.168.0.254 (192.168.0.1) from 00:16:3e:6f:99:86 (XENtest2) via eth0
Jul 4 10:26:48 CentOS dhcpd: DHCPACK on 192.168.0.254 to 00:16:3e:6f:99:86 (XENtest2) via eth0
Jul 4 10:26:48 CentOS dhcpd: DHCPDISCOVER from 00:16:3e:6f:99:86 (XENtest2) via eth0
Jul 4 10:26:48 CentOS dhcpd: DHCPOFFER on 192.168.0.254 to 00:16:3e:6f:99:86 (XENtest2) via eth0
Jul 4 10:26:48 CentOS dhcpd: DHCPREQUEST for 192.168.79.136 (192.168.79.254) from 00:16:3e:6f:99:86 via eth0: wrong network.
Jul 4 10:26:48 CentOS dhcpd: DHCPNAK on 192.168.79.136 to 00:16:3e:6f:99:86 via eth0

 

Zaujimave je, ze Centos2 dostane adresu od VMPlayera, aj ked je az druhy v poradi v DHCPDISCOVER a este i pise wrong network


[root@CentOS ~]# tcpdump -vv -s 0 -i eth0 port 67 || port 68
tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
10:26:46.132807 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 328) 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok] BOOTP/DHCP, Request from 00:16:3e:6f:99:86 (oui Unknown), length: 300, xid:0x118f9876, flags: [none] (0x0000)
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:DISCOVER
RQ:192.168.0.254
HN:"XENtest2"
PR:SM+BR+TZ+DG+DN+NS+HN+YD+YS+NTP+MTU
10:26:47.003151 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 336) 192.168.0.1.bootps > 192.168.0.254.bootpc: [udp sum ok] BOOTP/DHCP, Reply, length: 308, xid:0x118f9876, flags: [none] (0x0000)
Your IP: 192.168.0.254
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:OFFER
SID:192.168.0.1
LT:21600
SM:255.255.255.0
TZ:-18000
DG:192.168.79.2
DN:"mydomain.org"
NS:192.168.0.1
YD:"mydomain.org"
10:26:47.004239 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 328) 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok] BOOTP/DHCP, Request from 00:16:3e:6f:99:86 (oui Unknown), length: 300, xid:0x118f9876, flags: [none] (0x0000)
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:REQUEST
SID:192.168.0.1
RQ:192.168.0.254
HN:"XENtest2"
PR:SM+BR+TZ+DG+DN+NS+HN+YD+YS+NTP+MTU
10:26:47.004515 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 328) 192.168.79.254.bootps > 255.255.255.255.bootpc: [udp sum ok] BOOTP/DHCP, Reply, length: 300, xid:0x118f9876, flags: [Broadcast] (0x8000)
Server IP: 192.168.79.254
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:NACK
MSG:"requested address not available"
10:26:47.475027 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 328) 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok] BOOTP/DHCP, Request from 00:16:3e:6f:99:86 (oui Unknown), length: 300, xid:0x6f6be038, flags: [none] (0x0000)
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:DISCOVER
HN:"XENtest2"
PR:SM+BR+TZ+DG+DN+NS+HN+YD+YS+NTP+MTU
10:26:47.475638 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 328) 0.0.0.0.bootpc > 255.255.255.255.bootps: [udp sum ok] BOOTP/DHCP, Request from 00:16:3e:6f:99:86 (oui Unknown), length: 300, xid:0x6f6be038, flags: [none] (0x0000)
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:REQUEST
SID:192.168.79.254
RQ:192.168.79.136
HN:"XENtest2"
PR:SM+BR+TZ+DG+DN+NS+HN+YD+YS+NTP+MTU
10:26:48.054080 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 336) 192.168.0.1.bootps > 192.168.0.254.bootpc: [udp sum ok] BOOTP/DHCP, Reply, length: 308, xid:0x118f9876, flags: [none] (0x0000)
Your IP: 192.168.0.254
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:ACK
SID:192.168.0.1
LT:21600
SM:255.255.255.0
TZ:-18000
DG:192.168.79.2
DN:"mydomain.org"
NS:192.168.0.1
YD:"mydomain.org"
10:26:48.054289 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 336) 192.168.0.1.bootps > 192.168.0.254.bootpc: [udp sum ok] BOOTP/DHCP, Reply, length: 308, xid:0x6f6be038, flags: [none] (0x0000)
Your IP: 192.168.0.254
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:OFFER
SID:192.168.0.1
LT:21600
SM:255.255.255.0
TZ:-18000
DG:192.168.79.2
DN:"mydomain.org"
NS:192.168.0.1
YD:"mydomain.org"
10:26:48.054477 IP (tos 0x10, ttl 16, id 0, offset 0, flags [none], proto: UDP (17), length: 328) 192.168.0.1.bootps > 255.255.255.255.bootpc: [udp sum ok] BOOTP/DHCP, Reply, length: 300, xid:0x6f6be038, flags: [Broadcast] (0x8000)
Server IP: 192.168.0.1
Client Ethernet Address: 00:16:3e:6f:99:86 (oui Unknown)
Vendor-rfc1048:
DHCP:NACK
SID:192.168.0.1
MSG:"requested address not available"



 

[nicco]

Vypol som service vo Windowse zodpovednu za DHCP vo VMPlayerovi - VMware DHCP Service

[Michal Kubeček]

Mělo by to jít nakonfigurovat i přímo ve VMware (ve Workstation to jde určitě), navíc selektivně pro vybrané sítě.

[nicco]

Ale ak by niekto vedel povodnu pricinu preco sa tak deje, sem s nou. Nejako natavit moj dhcpd alebo klient dhcp...

[nicco]

Myslim, ze to ide, cez vmplayer-config.pl, ale je to komplikovane a zdlhave

[Hrubian]

Tam nejde vytvorit privatni segment site

[Hrubian]

Ustrelil jsem prilis brzo :) Doplnuji, co chybi:"? Dik"