DHCP relay agent


It is possible to configure multiple [DHCP relay agent](/dhcp-relay-agent)s on a single interface using the `ip helper-address` command like so:

```
interface GigabitEthernet0/1
 ip address 192.168.13.3 255.255.255.0
 ip helper-address 10.10.10.55
 ip helper-address 20.20.20.55
```

In such a case, DHCPDISCOVER messages are sent to all the helper addresses configured on the interface.  The client will obtain IP addressing information from whichever DHCP server responds first.  It's a similar situation to having two DHCP servers on the same subnet.  It's not ideal, as this can increase DHCP traffic on a network, but it is doable.

## Links

https://www.cisco.com/c/en/us/support/docs/ip/dynamic-address-allocation-resolution/27470-100.html

DHCP multiple IP helper-addresses

Cisco Quantum Flow Processor

Cisco SD-Access home lab

Cisco SD-WAN IPSec encapsulation on tunnel interface of vBond

Cisco SD-WAN Troubleshooting

Cisco SD-WAN backup vManage NMS configuration database

Cisco SD-WAN controller troubleshooting

Cisco SD-WAN export configs and files

Cisco SD-WAN export with python

Cisco SD-WAN lab options

Cisco SD-WAN rebranding

Cisco SD-WAN request upload

Cisco SD-WAN save command

Cisco SD-WAN scp command

Cisco SD-WAN vEdge Troubleshooting

Cisco SD-WAN vManage tail log

Cisco SD-WAN verify connectivity in Service VPN

Cisco SD-WAN viptela overlay network bringup

Cisco Switch Port Configuration for IP Phone

Cisco Validated Designs

Cisco's various lines of network switches

Class-Map - match statements

Classification and Marking of softphone applications

Cloud Service Model - Middleware

Cloud Service Model - Runtime

Cloud Service Models

Cloud service models - IaaS

Cloud service models - SaaS

CoPP - Best practices and operation

Configuration Register

Control Plane Policing (CoPP)

Control Plane Protection

DHCP - Broadcast flag

DHCP - Cisco Client ID format

DHCP - Client ID

DHCP - Commonly used options for IP phones

DHCP - DHCPv6 and the default gateway

DHCP - How a host is identified by a remote DHCP server

DHCP - Message Types

DHCP - Options

DHCP - Static binding use cases

DHCP - Understanding the Magic Cookie

DHCP - Using the MAC as the client ID on a Cisco device

DHCP Auto Image Update support

DHCP DORA process

DHCP Request message sent as broadcast

DHCP Snooping on a multi-switch topology

DHCP client options on Cisco IOS

DHCP decline message

DHCP excluding address on a Cisco IOS DHCP server

DHCP multiple servers on the same subnet

DHCP offer message sent as broadcast

DHCP option 82

DHCP relay support for MPLS VPN

DHCP renewal rebinding

DHCP snooping rate limiting best practice

DHCP trusted and untrusted ports

DHCP

DHCPv6 - Modes of Operation

DHCPv6 - determining the IPv6 prefix assigned to an interface

DHCPv6 lease times on a Cisco IOS device

DHCPv6 relay agent

DMVPN - Dual-Hub Single-Cloud with redundant spoke links config guidelines

DMVPN - IPsec encryption order of operations

DMVPN - NHRP purge request

DMVPN - NHRP session attributes

DMVPN - OSPF and multiple areas

DMVPN - Phase 2 BGP peerings

DMVPN - Phase 2 EIGRP neighbor adjacencies

DMVPN - Phase 2 OSPF neighbor adjacencies

DMVPN - Phase 2 and multicast traffic

DMVPN - Phase 2 and summarization

DMVPN - Using the GRE tunnel key

DMVPN - What is the best routing protocol to use

DMVPN - mappings on hub and spokes

DMVPN - multicast commands

DMVPN - nhrp map and nhs command syntax

DMVPN - spoke redundancy

DMVPN - using a default route

DMVPN State of a tunnel

DMVPN dual hub dual cloud

DMVPN dual hub single cloud

DMVPN hierarchical topology

DMVPN redundancy options

DMVPN with more than two hubs

DMVPN

DNS - Authoritative Flag

DNS - Authoritative Server

DNS - Caching

DNS - Recursive Resolver

DNS - What is a delegation zone

DNS - stub zone

DNS - understanding zones

DNS cache windows PC

DSL - Asymmetric Digital Subscriber Line (ADSL)

DTP - Sending of Frames

DTP - best practice to disable

DTP - how to disable

DHCP multiple IP helper-addresses

Links

Links to this page: