DHCP problem s pridelovanim IP

[Pavel]

Dobry den,

uz tu par dnu resim problem s pridelovanim IP adres na klienty pres
DHCP server. Na nekolika routerech asi 3 roky v provozu se najednou
nahodne zacaly objevovat problemy s pridelenim IP. V logu na serveru
je pouze toto stale dokola:

dhcpd: DHCPDISCOVER from 74:ea:3a:c3:fc:f1 via eth1
dhcpd: DHCPOFFER on 192.168.121.30 to 74:ea:3a:c3:fc:f1
(jmeno) via eth1

Puvodne sem to daval za vinu haveti na klientech ve Windows, jenze pak
to zacalo delat i na routerech TP link, ktere nekteri klienti maji. V
nich je v logu toto:

143     85642:DHCPC discovery timeout.
144     85648:DHCP client tx discover(B).
145     85676:Flags was changed to be 0x0.
146     85733:Flags was changed to be 0x0.
147     85766:DHCPC discovery timeout.
148     85772:DHCP client tx discover(B).
149     85800:Flags was changed to be 0x0.
150     85857:Flags was changed to be 0x0.
151     85890:DHCPC discovery timeout.
152     85896:DHCP client tx discover(B).
153     85924:Flags was changed to be 0x0.
154     85981:Flags was changed to be 0x0.

Kdyz nastavim pevne IP vse funguje. Z dalsich poznatku jsem vyloucil
problem na klientovi, nemuzu ale na routerech najit nic podezreleho,
je tam treba 50 klientu a dela to jen jedinemu. IP prideluji podle MAC
stale stejnou, zkousel sem problemovemu klientovi nabidnout i jinou IP
z rozsahu (range), ale taky si ji nevezme. Kdyz misto jeho PC pripojim
svuj notebook, svoji IP dostanu bez problemu. Pokud si naklonuji jeho
MAC, dostanu IP rovnez a pak uz dokud nevyprsi (1 den), to jede i
jemu.

Kdyz jsem se to snazil dumpnout, na nic sem neprisel:

20:26:12.199552 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 74:ea:3a:c3:fc:f1 (oui Unknown), length: 286
20:26:12.200531 IP 192.168.121.1.bootps > 255.255.255.255.bootpc: BOOTP/DHCP, Reply, length: 300

nebo -vv

20:33:15.201436 IP (tos 0x0, ttl  32, id 56078, offset 0, flags [DF], proto: UDP (17), length: 576) 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from
74:ea:3a:c3:fc:f1 (oui Unknown), length: 548, xid:0x5361d190, secs:26, flags: [Broadcast] (0x8000)
          Client Ethernet Address: 74:ea:3a:c3:fc:f1 (oui Unknown) [|bootp]
20:33:15.202578 IP (tos 0x0, ttl  64, id 0, offset 0, flags [DF], proto: UDP (17), length: 328) 192.168.121.1.bootps > 255.255.255.255.bootpc: BOOTP/DHCP, Reply, length: 300,
xid:0x5361d190, secs:26, flags: [Broadcast] (0x8000)
          Your IP: klient.domena.net (pozn. ciselne 192.168.121.3)
          Client Ethernet Address: 74:ea:3a:c3:fc:f1 (oui Unknown) [|bootp]
          

Dale jsem zkousel vymenit na routeru staricky dhcp za novejsi verzi,
bez vysledku. Vypnuti firewallu nema vliv. Distribuce je Slackware
10.2.0.

Napada nekoho kde hledat ?

Diky


Pavel