To bypass the load balancer:
1. SSH to a jump box which has network access to the TAS deployed VMs.
2. Using curl, verify if there is a valid HTTP response from the api.domain.
curl -kv api.domain
If this works, you should get a 200 OK or a 301 HTTP response. If you don't, this is an issue. Please proceed with the next steps.
3. If you do not know the VIP of the load balancer you can use ping (if allowed by firewall), dig, nslookup etc. to find it out.
Example:
ping api.domains.com
or
dig @<dns_server_ip> api.domain.com
or
nslookup api.domain.com
4. Note down the IP to make sure later by comparison that we have successfully bypassed it.
5. From bosh cli run bosh vms| grep -w "router" to get the IP address of any Gorouter.
6. Using text editor, modify the file /etc/hosts on your jump box to add a manual entry for one of the Gorouters pointing to the api.domain. DNS lookup should use the local /etc/hosts file as a first source and if an entry is not available then it queries the DNS server. This means that the manual entry will overwrite the DNS record from the DNS server.
Example:
7. Like in Step 3, check if the api.domain now resolves to the GorouterIP instead of the VIP of the load balancer. If it does, you have successfully bypassed the load balancer.
8. Using curl, verify if there is a valid HTTP response from the api.domain.
curl -kv api.domain
If this works, you should get a 200 OK or a 301 HTTP response.
Alternatively, you can send a curl request using a custom host header where you specify a Gorouter IP address. For this method, please follow this KB Article.