Fresh install, latest iso, network is broken

[sjtrotter]

Hi there. I am running a fresh install on an ESXi VM. Installing a thick manager node with 6 cpus, 16G ram, 512G storage.
Network setup is thru ESXi trunk to cisco trunk, verified working (see below).

Running the installer after first login. Get thru the networking bit, get to preflight checks and errors out on url accesses.
Log says:

Beginning pre-flight checks.
  Checking OS default repos with yum update.
Loaded plugins: fastestmirror, versionlock
Loading mirror speeds from cached hostfile
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was
14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error"


 One of the configured repositories failed (Unknown),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Run the command with the repository temporarily disabled
            yum --disablerepo=<repoid> ...

     4. Disable the repository permanently, so yum won't use it by default. Yum
        will then just ignore the repository until you permanently enable it
        again or use --enablerepo for temporary usage:

            yum-config-manager --disable <repoid>
        or
            subscription-manager repos --disable=<repoid>

     5. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=true

Cannot find a valid baseurl for repo: base/7/x86_64
  FAILURE

Pre-flight checks could not complete.

So I do some network troubleshooting.
Used nmtui to verify interface is active, and configured correctly.
Try pinging different things. No responses.
Log into my switch. Interface is up, no issues with spanning-tree etc. Trunk shows green. Can ping SO IP from switch...????
Log into firewall, can ping SO IP from there as well....
SSH into SO box....once again... ????
But still can't ping anything from SO (even the gateway or DNS server), also can't run a manual yum update...?

Wth is going on...? Any ideas..?

edit: also, have tried flushing all firewall rules and chains, and turning off firewalld.

[sjtrotter]

My fault. Had some firewall issues outside of the box. Testing now but should be okay from here.