How do I create a DHCP pool for a VLAN?
To create a DHCP pool and enter DHCP pool configuration mode, use the ‘ip dhcp pool [pool name]’ command. use the ‘network [network ID] [subnet mask]’ command to define the range of IP addresses. DHCP uses this range to provide IP configuration to clients.
How do I create a DHCP switch?
How to configure DHCP on a Cisco router or layer 3 switch
- Domain Name Router(dhcp–config)# domain-name MyNetwork.
- Lease Time 7 days Router(dhcp–config)# lease 7.
- Lease Time 12 hours Router(dhcp–config)# lease 0 12. To see DHCP leases that have been assigned, issue the following command. Router#show ip dhcp binding.
What is DHCP option pool?
DHCP pools allows for the configuration of of IP address pools for allocation by the system when acting as a DHCP server.
How many DHCP options are there?
ISC (Internet Systems Consortium) DHCP has five predefined option spaces: dhcp, agent, server, nwip, and fqdn.
What is option 82?
DHCP Option 82 is organized as a single DHCP option that contains information known by the relay agent. This feature provides additional security when DHCP is used to allocate network addresses, and enables the Cisco controller to act as a DHCP relay agent to prevent DHCP client requests from untrusted sources.
What is DHCP snooping Option 82?
The DHCP Option 82, aka Agent Relay Information Option or Agent Information Option, was originally created by RFC 3046 to allow the DHCP relay agent (e.g switch, router, firewall or server) to identify itself and the DHCP client that sent the original DHCP message.
What is IP DHCP snooping?
DHCP snooping is a security feature that acts like a firewall between untrusted hosts and trusted DHCP servers. The DHCP snooping feature performs the following activities: • Validates DHCP messages received from untrusted sources and filters out invalid messages.
Should I use DHCP snooping?
DHCP snooping is a layer 2 security technology built into the operating system of a capable network switch that drops DHCP traffic determined to be unacceptable. The fundamental use case for DHCP snooping is to prevent unauthorized (rogue) DHCP servers offering IP addresses to DHCP clients.
Why is DHCP snooping needed?
In computer networking, DHCP snooping is a series of techniques applied to improve the security of a DHCP infrastructure. DHCP servers allocate IP addresses to clients on a LAN. DHCP snooping can be configured on LAN switches to exclude rogue DHCP servers and remove malicious or malformed DHCP traffic.
How do I stop DHCP snooping?
- Enter system view. system-view.
- Enter interface view. interface interface-type interface-number.
- Disable DHCP snooping on the interface. dhcp snooping disable. By default: If you enable DHCP snooping globally or for a VLAN, DHCP snooping is enabled on all interfaces on the device or on all interfaces in the VLAN.
What is the two benefits of DHCP snooping?
DHCP snooping can prevent DHCP spoofing attacks. DHCP snooping is a Cisco Catalyst feature that determines which switch ports can respond to DHCP requests. Ports are identified as trusted and untrusted. Only ports that connect to an authorized DHCP server are trusted, and allowed to send all types of DHCP messages.
What is DHCP starvation attack?
DHCP starvation attack is an attack that targets DHCP servers whereby forged DHCP requests are crafted by an attacker with the intent of exhausting all available IP addresses that can be allocated by the DHCP server. Under this attack, legitimate network users can be denied service.
How do I enable DHCP snooping?
To begin enabling DHCP snooping, use the global command ip dhcp snooping as shown in Figure 1. Figure 1 Global enablement of DHCP snooping on a Cisco switch. Next, configure the VLANs you want to protect, using the command ip dhcp snooping vlan 99.
What is DHCP snooping and how it works?
DHCP Snooping is a layer 2 security technology incorporated into the operating system of a capable network switch that drops DHCP traffic determined to be unacceptable. DHCP Snooping prevents unauthorized (rogue) DHCP servers offering IP addresses to DHCP clients.
What is the effect of entering the IP DHCP?
What is the effect of entering the ip dhcp snooping configuration command on a switch? It enables DHCP snooping globally on a switch. It enables PortFast globally on a switch. It disables DTP negotiations on trunking ports.
Why does a Layer 2 switch need an IP address?
2 Answers. An IP address on a true layer 2 only switch is used for management (accessing the CLI remotely, sending SNMP traps, logging, TACACS/RADIUS, etc.). The IP address on the switch is in no way required for the switch to actually do its job, which is to switch frames.
What is dynamic ARP inspection?
Dynamic ARP Inspection (DAI) is a security feature that validates Address Resolution Protocol (ARP) packets in a network. DAI allows a network administrator to intercept, log, and discard ARP packets with invalid MAC address to IP address bindings.
What is the effect of entering the IP ARP Inspection VLAN 10 configuration command on a switch?
What is the effect of entering the ip arp inspection vlan 10 configuration command on a switch? It enables DHCP snooping globally on a switch. It specifies the maximum number of L2 addresses allowed on a port. It enables DAI on specific switch interfaces previously configured with DHCP snooping.
How do I enable ARP inspection?
You enable dynamic ARP inspection on a per-VLAN basis by using the ip arp inspection vlan vlan-range global configuration command. In non-DHCP environments, dynamic ARP inspection can validate ARP packets against user-configured ARP access control lists (ACLs) for hosts with statically configured IP addresses.
What is the effect of entering the IP ARP?
What is the effect of entering the ip arp inspection validate src-mac configuration command on a switch? It checks the source L2 address in the Ethernet header against the sender L2 address in the ARP body. It disables all trunk ports. It displays the IP-to-MAC address associations for switch interfaces.