The number of BGP neighbor route entries exceeds the limit.

Background: two lines used by our company, one of which is the MPLS line of China Telecom. We need to transmit the routes to the BGP Route of China Telecom, the BGP routing protocol of China Telecom is transmitted to the corresponding routing table of the headquarters.
Symptom:
Suddenly, the MPLS line of China Telecom was disconnected, and Netcare called to report the fault. I thought the optical fiber was disconnected and asked Netcare to arrange a cable search. After a while, the mail came over and said that the number of Route entries we published has exceeded the limit. Normally, we can only release up to 20 route entries.

Solution:
I immediately connected my company's core switch to view the route publishing status.
Show IP Route VPN 1
It seems that there is no abnormal route release.
Show IP subnet
Check the establishment of the Telecom eigrp1 directly connected to me. The status is as follows:

* Apr? 4 00:43:27. 599 GMT: % DUAL-5-NBRCHANGE: EIGRP-IPv4 1: Neighbor 172.16.183.249 (gigabitethernet1/0/1) is down: Holding Time expired

Clear IP subnet
It is useless to create a new neighbor.
Because the control end is on the computer's router, there is also a eigrp1 process.

At this time, I started to code people. I went to the telecom people and they logged on to their devices. It was just a check and there were no commands at all, later I found that the port connecting their device to my core is half duplex.
They enter the interface
Speed100
Fuplex full

In fact, this line is broken for a while. Then we can. So far, why does it mean that the number of BGP neighbor route entries exceeds the limit.
When dealing with such basic operators, the headache is their change process. You don't know who is going to change the configurations or will not notify the customers. There is no way at all.

The number of BGP neighbor route entries exceeds the limit.