Вроде нормальный запрос:

22:09:01.783764 00:1e:58:70:89:00 > 00:1b:21:86:a5:66, ethertype IPv4 (0x0800), length 590: (tos 0xfc, ttl 128, id 38314, offset 0, flags [none], proto UDP (17), length 576)
10.254.0.195.68 > 10.254.0.1.67: [udp sum ok] BOOTP/DHCP, Request from 00:03:0d:11:c3:dd, length 548, hops 1, xid 0x7c09, Flags [none] (0x0000)
Client-IP 46.44.18.23
Gateway-IP 10.254.0.195
Client-Ethernet-Address 00:03:0d:11:c3:dd
Vendor-rfc1048 Extensions
Magic Cookie 0x63825363
DHCP-Message Option 53, length 1: Request
Client-ID Option 61, length 7: ether 00:03:0d:11:c3:dd
Parameter-Request Option 55, length 6:
Subnet-Mask, Default-Gateway, Domain-Name-Server, Domain-Name
BR, Server-ID
Agent-Information Option 82, length 18:
Circuit-ID SubOption 1, length 6: ^@^D^@^J^@^Z
Remote-ID SubOption 2, length 8: ^@^F^@^^XpM-^I^@
END Option 255, length 0
PAD Option 0, length 0, occurs 267

Почему-то релеят все свитчи 3200-28 (1.52.B007) сегмента:

2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.148)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.149)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.70)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.248)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.97)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.176)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.44)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.194)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.220)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.54)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.99)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.27)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.188)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.28)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.197)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.167)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.165)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.174)
2011-10-12 22:09:01 [39859:1090562752] Got DHCPREQUEST (3) message from client 00:03:0D:11:C3:DD on vlan500/10.254.0.1 (relay 10.254.0.133)

А вот 3528 (он один стоял для тестов с этой прошивкой), с прошивкой 2.71.B037 вообще начинает сам флудить dhcp сервер запросами DHCPREQUEST, картина похожа на ту что выше, только адреса не разных свитчей, а этого 3528. При этом клиент с этим мак адресом находится за 2 свитча от 3528, и что самое смешное 3528 стоит последним в цепочке, самым дальним от dhcp сервера, он не транзитный, значит долетать запрос до него может только бродкастом. Такой глюк пока наблюдается только в с этим клиентом, и воспроизводится 100%.

Настройки везде одинаковые:
enable dhcp_relay
config dhcp_relay hops 4 time 0
config dhcp_relay option_82 state enable
config dhcp_relay option_82 check disable
config dhcp_relay option_82 policy keep
config dhcp_relay option_82 circuit_id default
config dhcp_relay option_82 remote_id default
config dhcp_relay add vlanid 10 10.254.0.1
config dhcp_relay add vlanid 10 10.254.0.2