Re: [VFKD] TC-4400 Log-Einträge abgeschnitten
Verfasst: 05.02.2021, 23:59
So hab ich es eigentlich auch in der Berufsschule gelernt.robert_s hat geschrieben: ↑05.02.2021, 23:33DHCP-Client Cache leeren oder Neustarten. Wenn Du nur mal kurz den Link wegnimmst, macht der Client die "verkürzte" Variante, in der er von dem zuletzt genutzten DHCP-Server die gleiche IP-Adresse noch mal anfordert, wie man in Deinem Capture sieht. Wenn der DHCP-Client "jungfräulich" ist, schickt der erst mal einen Broadcast, um einen DHCP-Server zu finden. Auf den kommt dann das DHCP OFFER Paket als Antwort.
Tadaaaa:
Code: Alles auswählen
root@router:~ # tcpdump -i igb0 -pvn port 67 and port 68 -vvvvvvvvvvv
tcpdump: listening on igb0, link-type EN10MB (Ethernet), capture size 262144 bytes
23:56:41.235655 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 40:62:31:11:b1:1f, length 300, xid 0x1264041c, Flags [none] (0x0000)
Client-Ethernet-Address 40:62:31:11:b1:1f
Vendor-rfc1048 Extensions
Magic Cookie 0x63825363
DHCP-Message Option 53, length 1: Discover
Client-ID Option 61, length 7: ether 40:62:31:11:b1:1f
Hostname Option 12, length 6: "router"
Parameter-Request Option 55, length 10:
Subnet-Mask, BR, Time-Zone, Classless-Static-Route
Default-Gateway, Domain-Name, Domain-Name-Server, Hostname
Option 119, MTU
END Option 255, length 0
PAD Option 0, length 0, occurs 27
23:56:41.245745 IP (tos 0x0, ttl 64, id 0, offset 0, flags [none], proto UDP (17), length 328)
88.134.228.2.67 > 24.134.XXX.XXX.68: [udp sum ok] BOOTP/DHCP, Reply, length 300, xid 0x1264041c, Flags [none] (0x0000)
Your-IP 24.134.XXX.XXX
Gateway-IP 83.169.169.94
Client-Ethernet-Address 40:62:31:11:b1:1f
Vendor-rfc1048 Extensions
Magic Cookie 0x63825363
DHCP-Message Option 53, length 1: Offer
Server-ID Option 54, length 4: 88.134.228.2
Lease-Time Option 51, length 4: 4666
Subnet-Mask Option 1, length 4: 255.255.255.252
BR Option 28, length 4: 255.255.255.255
Domain-Name-Server Option 6, length 8: 88.134.228.33,88.134.228.97
Default-Gateway Option 3, length 4: 24.134.XXX.XXX
END Option 255, length 0
PAD Option 0, length 0, occurs 16
23:56:43.144262 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 40:62:31:11:b1:1f, length 300, xid 0x1264041c, Flags [none] (0x0000)
Client-Ethernet-Address 40:62:31:11:b1:1f
Vendor-rfc1048 Extensions
Magic Cookie 0x63825363
DHCP-Message Option 53, length 1: Request
Server-ID Option 54, length 4: 88.134.228.2
Requested-IP Option 50, length 4: 24.134.XXX.XXX
Client-ID Option 61, length 7: ether 40:62:31:11:b1:1f
Hostname Option 12, length 6: "router"
Parameter-Request Option 55, length 10:
Subnet-Mask, BR, Time-Zone, Classless-Static-Route
Default-Gateway, Domain-Name, Domain-Name-Server, Hostname
Option 119, MTU
END Option 255, length 0
PAD Option 0, length 0, occurs 15
23:56:43.162997 IP (tos 0x0, ttl 64, id 0, offset 0, flags [none], proto UDP (17), length 328)
88.134.228.2.67 > 24.134.XXX.XXX.68: [udp sum ok] BOOTP/DHCP, Reply, length 300, xid 0x1264041c, Flags [none] (0x0000)
Your-IP 24.134.XXX.XXX
Gateway-IP 83.169.169.94
Client-Ethernet-Address 40:62:31:11:b1:1f
Vendor-rfc1048 Extensions
Magic Cookie 0x63825363
DHCP-Message Option 53, length 1: ACK
Server-ID Option 54, length 4: 88.134.228.2
Lease-Time Option 51, length 4: 4664
Subnet-Mask Option 1, length 4: 255.255.255.252
BR Option 28, length 4: 255.255.255.255
Domain-Name-Server Option 6, length 8: 88.134.228.33,88.134.228.97
Default-Gateway Option 3, length 4: 24.134.XXX.XXX
END Option 255, length 0
PAD Option 0, length 0, occurs 16
Maxi
