DHCP:DISCOVER 의 request 패킷 구조. dhcp 서버가 응답이 있을때까지 보낸다. secs는 Sequence를 말하는 것으로 보임.
아래 예정에서는 secs 39에서 응답이 오기 시작함.
DISCOVER에서 자신의 MAC과 HN(호스트네임) 그리고 요청값을 보낸다. 이에 대한 응답은 DHCP:OFFER를 통해 받는데
이 패킷안에 client의 ip 및 dns, gateway, netmasks 정보가 담겨져 있다.
DCHP:REQUEST 형태로 SID,RQ를 채워서 보낸다. 이에 대한 응답으로 DHCP:ACK 형태로 응답하는데 최종적인 값을 포함하고 있다.
DHCP:DISCOVER와 DHCP:REQUEST는 클라이언트에서 발생되며
DCHP:OFFER와 DHCP:ACK는 DHCP 서버의 응답을 DHCP Relay (보통 게이트웨이) 서버가 클라이언트에게 전달하는 형태이다.
중요한 것은 cid 값과 client의 mac이 같아야 정상적으로 ip를 할당 받을 수 있다.
19:13:38.789810 (tos 0x10, ttl 16, length: 328) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, length: 300
Request, xid:0x16c6e0b8
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:DISCOVER
LT:84000
CID:[type-48]30:3a:30:38:3a:38:38:3a:30:36:3a:31:36:3a:42:34
HN:"ana-eth0"
PR:SM+DN+DG+NS
19:13:40.786674 (tos 0x10, ttl 16, length: 328) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, length: 300
Request, xid:0x16c6e0b8, secs:3
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:DISCOVER
LT:84000
CID:[type-48]30:3a:30:38:3a:38:38:3a:30:36:3a:31:36:3a:42:34
HN:"ana-eth0"
PR:SM+DN+DG+NS
19:13:43.786647 (tos 0x10, ttl 16, length: 328) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, length: 300
Request, xid:0x16c6e0b8, secs:6
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:DISCOVER
LT:84000
CID:[type-48]30:3a:30:38:3a:38:38:3a:30:36:3a:31:36:3a:42:34
HN:"ana-eth0"
PR:SM+DN+DG+NS
19:13:49.786646 (tos 0x10, ttl 16, length: 328) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, length: 300
Request, xid:0x16c6e0b8, secs:12
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:DISCOVER
LT:84000
CID:[type-48]30:3a:30:38:3a:38:38:3a:30:36:3a:31:36:3a:42:34
HN:"ana-eth0"
PR:SM+DN+DG+NS
19:13:58.786647 (tos 0x10, ttl 16, length: 328) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, length: 300
Request, xid:0x16c6e0b8, secs:21
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:DISCOVER
LT:84000
CID:[type-48]30:3a:30:38:3a:38:38:3a:30:36:3a:31:36:3a:42:34
HN:"ana-eth0"
PR:SM+DN+DG+NS
19:14:16.916649 (tos 0x10, ttl 16, length: 328) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, length: 300
Request, xid:0x16c6e0b8, secs:39
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:DISCOVER
LT:84000
CID:[type-48]30:3a:30:38:3a:38:38:3a:30:36:3a:31:36:3a:42:34
HN:"ana-eth0"
PR:SM+DN+DG+NS
19:14:16.929288 (tos 0x0, ttl 255, length: 328) 59.9.167.254.67 > 59.9.167.141.68: [udp sum ok] BOOTP/DHCP, length: 300
Reply, xid:0x16c6e0b8
Your IP: 59.9.167.141
Server IP: 121.138.7.42
Gateway IP: 59.9.167.254
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:OFFER
SID:121.138.7.42
SM:255.255.255.0
DG:59.9.167.254
NS:168.126.63.1,168.126.63.2
DN:"kornet"
LT:3600
19:14:18.949706 (tos 0x10, ttl 16, length: 328) 0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, length: 300
Request, xid:0x16c6e0b8, secs:39
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:REQUEST
SID:121.138.7.42
LT:84000
RQ:59.9.167.141
CID:[type-48]30:3a:30:38:3a:38:38:3a:30:36:3a:31:36:3a:42:34
HN:"ana-eth0"
PR:SM+DN+DG+NS
19:14:18.962274 (tos 0x0, ttl 255, length: 328) 59.9.167.254.67 > 59.9.167.141.68: [udp sum ok] BOOTP/DHCP, length: 300
Reply, xid:0x16c6e0b8
Your IP: 59.9.167.141
Server IP: 121.138.7.42
Gateway IP: 59.9.167.254
Client Ethernet Address: 00:08:88:06:16:b4
Vendor-rfc1048:
DHCP:ACK
SID:121.138.7.42
SM:255.255.255.0
DG:59.9.167.254
NS:168.126.63.1,168.126.63.2
DN:"kornet"
LT:3600