DHCP Relay 后dhcp相关流量绕过CP

[wanghaitao]

本帖最后由 C1whaitao 于 2015-10-12 16:24 编辑
最近遇到一个问题：DHCP Relay 后dhcp相关流量绕过CP,请问怎么处理才能避免。最终使DHCP相关流量经过CP?

interface Vlan2

description Client

vrf forwarding Client

ip address 192.168.100.1 255.255.255.0

ip helper-address vrf Server 192.168.1.254

end

!

拓扑：

[taosun2 · Accepted solution]

联系CISCO开CASE咨询一下吧.

[wanghaitao]

本帖最后由 C1whaitao 于 2017-10-27 15:36 编辑
Debug:
SW01#debug ip dhcp server packet
DHCP server packet debugging is on.
SW01#ter moni
SW01#
.Oct 10 2015 17:44:44.283: DHCPD: Reload workspace interface Vlan2 tableid 3.
.Oct 10 2015 17:44:44.283: DHCPD: tableid for 192.168.100.1 on Vlan2 is 3
.Oct 10 2015 17:44:44.283: DHCPD: client's VPN is Client.
.Oct 10 2015 17:44:44.284: DHCPD: DHCPREQUEST received from client 0128.d244.aad7.e0.
.Oct 10 2015 17:44:44.284: DHCPD: Finding a relay for client 0128.d244.aad7.e0 on interface Vlan2.
.Oct 10 2015 17:44:44.284: DHCPD: Looking up binding using address 192.168.100.1
.Oct 10 2015 17:44:44.284: DHCPD: setting giaddr to 192.168.100.1.
.Oct 10 2015 17:44:44.284: DHCPD: BOOTREQUEST from 0128.d244.aad7.e0 forwarded to 192.168.1.254.
.Oct 10 2015 17:44:44.287: DHCPD: Reload workspace interface Vlan11 tableid 3.
.Oct 10 2015 17:44:44.287: DHCPD: tableid for 192.168.200.129 on Vlan11 is 3
.Oct 10 2015 17:44:44.287: DHCPD: client's VPN is .
.Oct 10 2015 17:44:44.287: DHCPD: forwarding BOOTREPLY to client 28d2.44aa.d7e0.
.Oct 10 2015 17:44:44.287: DHCPD: no option 125
.Oct 10 2015 17:44:44.287: DHCPD: broadcasting BOOTREPLY to client 28d2.44aa.d7e0.
.Oct 10 2015 17:44:44.659: DHCPD: Reload workspace interface Vlan2 tableid 3.
.Oct 10 2015 17:44:44.659: DHCPD: tableid for 192.168.100.1 on Vlan2 is 3
.Oct 10 2015 17:44:44.659: DHCPD: client's VPN is Client.
.Oct 10 2015 17:44:44.659: DHCPD: DHCPINFORM received from client 0128.d244.aad7.e0 (192.168.100.32).
.Oct 10 2015 17:44:44.659: DHCPD: Finding a relay for client 0128.d244.aad7.e0 on interface Vlan2.
.Oct 10 2015 17:44:44.659: DHCPD: Looking up binding using address 192.168.100.1
.Oct 10 2015 17:44:44.659: DHCPD: setting giaddr to 192.168.100.1.
.Oct 10 2015 17:44:44.659: DHCPD: BOOTREQUEST from 0128.d244.aad7.e0 forwarded to 192.168.1.254.
.Oct 10 2015 17:44:44.661: DHCPD: Reload workspace interface Vlan604 tableid 3.
.Oct 10 2015 17:44:44.661: DHCPD: tableid for 192.168.200.129 on Vlan11 is 3
.Oct 10 2015 17:44:44.661: DHCPD: client's VPN is .
.Oct 10 2015 17:44:44.661: DHCPD: forwarding BOOTREPLY to client 28d2.44aa.d7e0.
.Oct 10 2015 17:44:44.661: DHCPD: no option 125
.Oct 10 2015 17:44:44.661: DHCPD: broadcasting BOOTREPLY to client 28d2.44aa.d7e0.
SW01#un all
All possible debugging has been turned off
SW01#exit

[wanghaitao]

若使用：
int vlan2
ip helper-address 192.168.1.254
则access vlan 2 的客户端，无法获取到地址

[wanghaitao]

taosun2 发表于 2015-10-18 11:42
联系CISCO开CASE咨询一下吧.

谢谢，原因已找到，DHCP流量被NAT了。所以客户端拿不到地址。

[Yanli Sun]

C1whaitao 发表于 2015-10-19 16:50
谢谢，原因已找到，DHCP流量被NAT了。所以客户端拿不到地址。

感谢分享问题解决办法 :handshake