某局点6850配置GRE后隧道接口无法起来

现场需要配置跨leaf的三层远程镜像，采用GRE tunnel的方式

现场按照正常的GRE配置后，发现tunnel无法up

打开debug tunnel all，发现有如下提示：

Tunnel1024 can"t come up because there is no enough hardware resource.

 Processing result of operation 2 for Tunnel1024: failed.

检查配置发现，现场还有另外一组tunnel采用了和gre tunnel一样的源目ip，由于tunnel4先创立的，tunnel1024是后创立的，所以只有tunnel4能起来，tunnel1024报资源不足。这是因为源目相同的时候只能存在一个tunnel

Tunnel4

Current state: UP

Line protocol state: UP

Description: Tunnel4 Interface

Bandwidth: 64 kbps

Maximum transmission unit: 1464

Internet protocol processing: Disabled

Last clearing of counters: 05:18:15 Fri 02/16/2001

Tunnel source 10.108.4.20, destination 10.108.4.21

Tunnel protocol/transport UDP_VXLAN/IP

Last 300 seconds input rate: 0 bytes/sec, 0 bits/sec, 0 packets/sec

Last 300 seconds output rate: 0 bytes/sec, 0 bits/sec, 0 packets/sec

Input: 0 packets, 0 bytes, 0 drops

Output: 0 packets, 0 bytes, 0 drops

建立GRE tunnel采用另外一对源目IP建立即可