Íåîæèäàííûå ïðîáëåìû ñ DNS è DHCP

**AndrewN** · 25-02-2008, 06:16

Originally Posted by Oleg

Ñ êàêîãî ïåðåïîþ îíè øëþò îòâåò 10.6.4.106, åñëè àäðåñ åù¸ íå ïðèñâîåí?

Òàê øëþò, òî îíè åãî ïî ïðàâèëüíîìó ìàêó. È ñ îïöèåé -r àäðåñ íå ïîäáèðàåò.

**Oleg** · 25-02-2008, 06:19

Çíà÷èò äåëî â ÷¸ì-òî äðóãîì. DN òóò íèêàêèì áîêîì.

**AndrewN** · 25-02-2008, 06:21

Originally Posted by Oleg

Çíà÷èò äåëî â ÷¸ì-òî äðóãîì. DN òóò íèêàêèì áîêîì.

Â îòâåòàõ ñåðâåðà åñòü åù¸ T249. ß òàê ïîíèìàþ ýòî ìàðøðóòû?

**Oleg** · 25-02-2008, 06:22

Äà, ìàðøðóòû.

**Oleg** · 25-02-2008, 06:23

Òîëüêî â îòâåòàõ ÿ èõ íå âèæó. Â çàïðîñå âèæó.

**AndrewN** · 25-02-2008, 06:25

Originally Posted by Oleg

Äà, ìàðøðóòû.

ßñíî. Çíà÷èò è íå â íèõ, ò.ê. ðàíüøå ðàáîòàëî. Ïðîáûâàë íåñêîëüêî ïðîøèâîê (8, 8.12, 8.14, 8.19). Îäíà è òà æå ïåòðóøêà íà âñåõ.

**AndrewN** · 25-02-2008, 06:27

Originally Posted by Oleg

Òîëüêî â îòâåòàõ ÿ èõ íå âèæó. Â çàïðîñå âèæó.

Èõ òàì ìíîãî. ß íå ñòàë èõ âñòàâëÿòü. Åñëè ýòî âàæíî, òî ìîãó åù¸ ðàç îòâåò çàïîñòèòü.

**AndrewN** · 25-02-2008, 06:36

Îòâåò ïîëíîñòüþ:

PHP Code:


09:28:13.414577 IP (tos 0x0, ttl  63, id 106, offset 0, flags [DF], length: 578) 10.6.1.1.67 > 10.6.4.106.68: [udp sum ok] BOOTP/DHCP, Reply, length: 550, hops:2, xid:0x6d2cd001, secs:3, flags: [none] (0x0000)

          Your IP: 10.6.4.106

          Gateway IP: 10.6.1.1

          Client Ethernet Address: 00:0c:6e:38:42:81

          Vendor-rfc1048:

            DHCP:OFFER

            SID:10.100.0.11

            LT:54000

            SM:255.255.240.0

            DG:10.6.1.1

            NS:10.100.0.11

            DN:"psk-net.ru"

            T249:6336,43208,2566,257,6154,25600,2566,257,5130,256,2566,257,5130,512,2566,257,5130,768,2566,257,5130,1280,2566,257,5130,1792,2566,257,7690,65021,33802,1537,269,2760,2566,257,3082,53258,1537,269,2632,2566,257,5723,51424,2566,257,5824,43088,2566,257,6336,43223,2566,257,7616,43008,2058,1537,284,49320,16,2566,257,7104,43008,8202,1537,282,49320,64,2566,257,6336,43009,2566,257,6080,43010,2566,257,5824,43012,2566,257,5568,43016,2566,257,5312,43024,2566,257,6336,43209,2566,257,6336,43200,2566,257,6080,43210,2566,257,5824,43212,2566,257,5312,43216,2566,257,6339,61310,2566,257,6339,61317,2566,257

**Oleg** · 25-02-2008, 07:17

Ðàç ðàíüøå ðàáîòàëî, à òåïåðü ñ òîé æå âåðñèåé íåò, òî î÷åâèäíî, ÷òî äåëî íå â ïðîøèâêå... Ìåíÿ ñìóùàåò èìåííî òî, ÷òî îòâåò íå áðîàäêàñòíûé.

**AndrewN** · 25-02-2008, 13:07

Âçÿë âåðñèþ udhcpc èç svn. Êîìïèëüíóë ñ äåáàãîì.
Ðàáîòàåò.

PHP Code:


 ./udhcpc -i vlan1 -s /usr/local/root/showparams 

udhcpc (v0.9.9-pre) started

adapter index 6

adapter hardware address 00:0c:6e:38:42:81

vforking and execle'ing /usr/local/root/showparams

deconfig

entering raw listen mode

Opening raw socket on ifindex 6

adding option 0x35

adding option 0x3d

adding option 0x3c

Sending discover...

Waiting on select...

oooooh!!! got some!

adding option 0x35

adding option 0x3d

adding option 0x3c

adding option 0x32

adding option 0x36

Sending select for 10.6.4.106...

Waiting on select...

oooooh!!! got some!

Lease of 10.6.4.106 obtained, lease time 54000

vforking and execle'ing /usr/local/root/showparams

bound

entering none listen mode

Ïðè ýòîì tcpdump ïîêàçûâàåò ñëåäóþùåå:

PHP Code:


tcpdump: listening on vlan1, link-type EN10MB (Ethernet), capture size 1500 bytes

16:01:12.141515 IP (tos 0x0, ttl  64, id 0, offset 0, flags [none], length: 576) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 00:0c:6e:38:42:81, length: 548, xid:0x8824b449, flags: [none] (0x0000)

          Client Ethernet Address: 00:0c:6e:38:42:81

          Vendor-rfc1048:

            DHCP:DISCOVER

            CID:[ether]00:0c:6e:38:42:81

            VC:"udhcp 0.9.9-pre"

            PR:SM+DG+NS+HN+DN+BR+YD+YS+NTP

16:01:12.145112 IP (tos 0x0, ttl  63, id 43342, offset 0, flags [DF], length: 334) 10.6.1.1.67 > 10.6.4.106.68: [udp sum ok] BOOTP/DHCP, Reply, length: 306, hops:2, xid:0x8824b449, flags: [none] (0x0000)

          Your IP: 10.6.4.106

          Gateway IP: 10.6.1.1

          Client Ethernet Address: 00:0c:6e:38:42:81

          Vendor-rfc1048:

            DHCP:OFFER

            SID:10.100.0.11

            LT:54000

            SM:255.255.240.0

            DG:10.6.1.1

            NS:10.100.0.11

            DN:"psk-net.ru"

16:01:12.148293 IP (tos 0x0, ttl  64, id 0, offset 0, flags [none], length: 576) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 00:0c:6e:38:42:81, length: 548, xid:0x8824b449, flags: [none] (0x0000)

          Client Ethernet Address: 00:0c:6e:38:42:81

          Vendor-rfc1048:

            DHCP:REQUEST

            CID:[ether]00:0c:6e:38:42:81

            VC:"udhcp 0.9.9-pre"

            RQ:10.6.4.106

            SID:10.100.0.11

            PR:SM+DG+NS+HN+DN+BR+YD+YS+NTP

16:01:12.151933 IP (tos 0x0, ttl  63, id 43346, offset 0, flags [DF], length: 334) 10.6.1.1.67 > 10.6.4.106.68: [udp sum ok] BOOTP/DHCP, Reply, length: 306, hops:2, xid:0x8824b449, flags: [none] (0x0000)

          Your IP: 10.6.4.106

          Gateway IP: 10.6.1.1

          Client Ethernet Address: 00:0c:6e:38:42:81

          Vendor-rfc1048:

            DHCP:ACK

            SID:10.100.0.11

            LT:54000

            SM:255.255.240.0

            DG:10.6.1.1

            NS:10.100.0.11

            DN:"psk-net.ru"

**AndrewN** · 25-02-2008, 13:24

Îëåã,
Ó ìåíÿ òóò ìûñëü âîçíèêëà. Ìîæåò udhcpc èç ïðîøèâêè æäåò ïàêåò ñ íå òåì mac àäðåñîì?

**Oleg** · 25-02-2008, 13:36

Êàê ýòî?

**AndrewN** · 25-02-2008, 17:27

Originally Posted by Oleg

Ðàç ðàíüøå ðàáîòàëî, à òåïåðü ñ òîé æå âåðñèåé íåò, òî î÷åâèäíî, ÷òî äåëî íå â ïðîøèâêå... Ìåíÿ ñìóùàåò èìåííî òî, ÷òî îòâåò íå áðîàäêàñòíûé.

Ïðî íå áðîàäêàñòíûé îòâåò åñòü â îïèñàíèè ïðîòîêîëà BOOTP ñëåäóùåå (ñì. ï. 2a):

PHP Code:


4. Chicken / Egg Issues

   How can the server send an IP datagram to the client, if the client
   doesnt know its own IP address (yet)?  Whenever a bootreply is being
   sent, the transmitting machine performs the following operations:

      1. If the client knows its own IP address ('ciaddr' field is
      nonzero), then the IP can be sent 'as normal', since the client
      will respond to ARPs [5].

      2. If the client does not yet know its IP address (ciaddr zero),
      then the client cannot respond to ARPs sent by the transmitter of
      the bootreply.  There are two options:

         a. If the transmitter has the necessary kernel or driver hooks


Croft & Gilmore                                                 [Page 4]



RFC 951                                                   September 1985
Bootstrap Protocol


         to 'manually' construct an ARP address cache entry, then it can
         fill in an entry using the 'chaddr' and 'yiaddr' fields.  Of
         course, this entry should have a timeout on it, just like any
         other entry made by the normal ARP code itself.  The
         transmitter of the bootreply can then simply send the bootreply
         to the client's IP address.  UNIX (4.2 BSD) has this
         capability.

         b. If the transmitter lacks these kernel hooks, it can simply
         send the bootreply to the IP broadcast address on the
         appropriate interface.  This is only one additional broadcast
         over the previous case.

Â îáùåì âñ¸ êàê-òî ñòðàííî...

**Oleg** · 25-02-2008, 17:57

Ïîïðîáóéòå ñîáðàòü áèçèáîêñíûé udhcpc ñ îòëàäêîé è ïîñìîòðåòü â ÷¸ì äåëî.

**AndrewN** · 25-02-2008, 19:03

òàê âðîäå åãî è áðàë svn://busybox.net/trunk/udhcp
Èëè Âû íå ýòî èìåëè ââèäó?

åù¸ íàïðÿãàåò ðóãàíü íà vlan1 ïðîøèâî÷íîãî êëèåíòà:

udhcpc -i vlan1 -s /tmp/udhcpc
udhcpc (v0.9.9-pre) started
vlan1: No such process
Sending discover...
Sending discover...
Sending discover...

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