Hello to the community,
I am prepering for my CCNA exam and have the following task and issue:
I Have the following network devices in gns3:
- R1: c3725 router and works as DHCP Server
- ESW1: a c3745 Router with NM-16ESW Slot, therefore operates es L3 Switch
- PC1: Is VPCS
Here the network topology:
- R1 f0/0 connected to ESW1 f1/0
- PC1 e0 connected to ESW1 f1/1
I have the following tasks:
1) Exclude first 10 IP addresses in subnet from pool
Pool name = vlan10
2) Network = 10.1.10.0/24 (Vlan 10)
3) Default Gateway = ESW1
4) DNS Server = R1
5) Make sure PC can ping the loopback of R1
6) Configure IP Helper, so PC1 can send DHCP Discover to R1
Here the IP Plan:
R1 f0/0: 10.1.1.254/24
R1 Loopback: 1.1.1.1/32
ESW1 f1/0: 10.1.1.1/24, and belongs to int vlan1
ESW1 f1/1: 10.1.10.1/24, and belongs to int vlan10
I have configured everything as it has to be configured. I can ping the loopback on R1 from the PC1 and back, but when PC1 sends DHCP Discover, R1 does recieve it, but doesn't send a DHCP offer. And i don't understand why. Because in Packet Tracer the same configuration works fine, but in gns3 it doesn't.
Here the output on R1 after i habe enabled debug ip hdcp packet:
*Mar 1 01:59:10.971: UDP: rcvd src=0.0.0.0(68), dst=10.1.1.1(67), length=372
*Mar 1 01:59:10.971: DHCPD: DHCPDISCOVER received from client 0100.5079.6668.00 on interface FastEthernet0/0.
R1#
*Mar 1 01:59:11.975: UDP: rcvd src=0.0.0.0(68), dst=10.1.1.1(67), length=372
*Mar 1 01:59:11.975: DHCPD: DHCPDISCOVER received from client 0100.5079.6668.00 on interface FastEthernet0/0.
R1#
*Mar 1 01:59:14.987: UDP: rcvd src=0.0.0.0(68), dst=10.1.1.1(67), length=372
*Mar 1 01:59:14.987: DHCPD: DHCPDISCOVER received from client 0100.5079.6668.00 on interface FastEthernet0/0.
R1#
*Mar 1 02:19:26.947: UDP: rcvd src=0.0.0.0(68), dst=255.255.255.255(67), length=372
*Mar 1 02:19:26.947: DHCPD: DHCPDISCOVER received from client 0100.5079.6668.00 on interface FastEthernet0/0.
R1#
*Mar 1 02:19:27.951: UDP: rcvd src=0.0.0.0(68), dst=255.255.255.255(67), length=372
*Mar 1 02:19:27.955: DHCPD: DHCPDISCOVER received from client 0100.5079.6668.00 on interface FastEthernet0/0.
R1#
*Mar 1 02:19:30.963: UDP: rcvd src=0.0.0.0(68), dst=255.255.255.255(67), length=372
*Mar 1 02:19:30.963: DHCPD: DHCPDISCOVER received from client 0100.5079.6668.00 on interface FastEthernet0/0.
R1#
Does anyone have an idea, why it doesn't work in gns3? May be there is some issue with the L3 switch? Or something of that kind?
