Connection failure from MC to cas after upgrade to CAS 3.2.2.1

Products

• ISG Content Analysis
• Management Center - VA

Issue/Introduction

Concerning the CAS, there is the docker bridge interface, as seen in the TS log. See the below.

[
    {
        "Name": "bridge",
        "Id": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
        "Created": "xxxx-07-07T12:23:58.xxxxxxxxxxxxxxxxx",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": null,
            "Config": [
                {
                    "Subnet": "x.x.0.0/16",
                    "Gateway": "x.x.0.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Ingress": false,
        "ConfigFrom": {
            "Network": ""
        },
        "ConfigOnly": false,
        "Containers": {},
        "Options": {
            "com.docker.network.bridge.default_bridge": "true",
            "com.docker.network.bridge.enable_icc": "true",
            "com.docker.network.bridge.enable_ip_masquerade": "true",
            "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0",
            "com.docker.network.bridge.name": "docker0",
            "com.docker.network.driver.mtu": "1500"
        },
        "Labels": {}
    }
]

Environment

CAS 3.2.2.1/MC 3.x.x.x

Cause

This is completely an address/routing issue, as a result of a conflict between addresses/subnets within the customer's environment and the docker bridge network within the CAS. 

Resolution

This is an address/routing issue on CAS, witt the fix provided in CAS 4.1.1.x. An upgrade of the MC to ver. 4.1.1.1 would not fix this address/routing issue. 

Workaround:

CAS(config)# ip route <Connected MC_IP> /32 <Default Gateway for Connected CAS_IP> device-name 0:0

This would be addressing the specific connectivity issue, a static route that allows every traffic intended for the MC, x.x.x.x/32 to go through the particular default gateway for the CAS.