DHCP Relay Packet Internet Tour

Source: Internet
Author: User
Tags system log server port

I. Overview:

The second layer of many experiments with GNS can not be simulated, IOU most of the only command can not see the effect, very easy to have the opportunity to log into the rack to do the experiment, did the DHCP snooping experiment, found Cisco router if as a DHCP server, must be configured IPDHCP relay information Trusted, otherwise the client will not be able to obtain the IP address, if you want the DHCP server to use Windows 2003, then add the 2003 DHCP service to the logon rack, but find that the DHCP service is not available, query the system log, Because this is in the workgroup 2003 with a domain control, it also ran DHCP, a mountain can not two tigers, encounter the genuine DHCP, my team's DHCP can only stay on the side.

After instructions, domain control can not let me log in to test, and the server does not allow the installation of virtual machine software, during the attempt to modify the test server subnet mask, no effect, if you want to borrow external DHCP to do the test, the following is a few tests:

A. Virtual machine (DHCP server) + host port forwarding +gns test

B.ezvpn dial-in + Test Server port forwarding + connecting rack test

C.DHCP server at the same time VPN server, PC1 dial vpn+gns, directly using the routing method test

D. Virtual machine (DHCP server, VPN server) + host port forwarding (simultaneous dial-in VPN) +gns test

Two. Virtual machine (DHCP server) + host port forwarding +gns test:

A. Test results:

---success

B. Test topology:

C. Configuration Description:

①PC1 is actually a host, configured with UDP port forwarding

② the port address of the router relay agent is the same as that of the host, because the DHCP server returns the packet based on the address of the DHCP relay in the DHCP unicast packet without looking at the address of the UDP three-layer header that reached it

③ Port forwarding requires two directions because of the characteristics of the DHCP server back pack

④R2 is configured with static NAT because of the need to ensure that UDP port forwarding, the data back to the relay proxy port address

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.