Hi,
We have a problem to bring a new 3750 switch interface up with the ISP.
Current interface configuration on the router 7500 with SC/Single mode 1000 Base LX is
interface GigabitEthernet4/0/0
description ###### ISP #######
ip address 1.1.1.2 255.255.255.252
no ip redirects
no ip unreachables
load-interval 30
no negotiation auto
no cdp enable
end
works perfectly fine.
we are trying to move this link to a Cisco 3750G on SFP single mode 1000 baase LX with the same configuration as below
interface GigabitEthernet1/0/51
no switchport
ip address 1.1.1.2 255.255.255.252
load-interval 30
no ip redirects
no ip unreachables
no cdp enable
speed nonegotiate
we dont get any errors on the link but it fails to learn the mac address from the isp.
checked the following.
1. tried changing the SFP and the fiber.
2. checked internally connecting back to back with another cisco device - works fine .
3. checked with the isp for any static arp on their side and it is a no.
I am wondering why it fails to learn the mac-address when it can self ping its own ip address and also the layer stays up with no errors on both the sides.
Thanks
