05-19-2014 02:26 PM - edited 03-07-2019 07:28 PM
Hello friends, I wrote these lines because a very strange and particular issue happened in my network.
There is a drawing of my topology:
I will explain first:
1. I have a big network (172.16.0.0/16) so I'm planning to cut it in VLANs. Since the network is 24/7 alive, I can't cut the service at once, so I decide to have 2 links: one in Layer 3 and another one in Layer 2. It works perfectly
2. I'm using the switch Core as ISP, so there is a default route from Distribution to Core
3. As I can't configure the access switch (port labeled as switchport), I let the ports in L2. The green line means that the port in distribution switch is in L3 and port in access switch is in L2
The issue: All the PCs in my network got the message of Duplicate IP, guess with which ip we had the issue? Well, it was with the L3 interface in distribution switch
My question is, what this could happen?! PCs are in 172.16.0.0/16 network and the L3 link is 10.0.0.0/32 network, at my sight, it is impossible
What do you think?
Thanks in advance for your answers!
09-15-2014 03:36 AM
What is the IP address of DHCP server ? Can you do a show ip with all association IP address - MAC address ?
09-15-2014 09:39 AM
Walter, I wasn't using a DHCP server, everything was configured with static IP.
09-16-2014 12:08 AM
What is the message ? IP 172.16.x.x duplicate ip with 10.0.0.x ?
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