Can you draw it?
The Aruba 2530 has no routing features so you really need to use an
external router to route between directly connected VLANs.
Suppose you have VLAN 10 and 20 defined and addressed on your Router, say
10.0.10.254 and 10.0.20.254 just as example (that way the router is
configured to act as the "gateway" for its connected peers located on those
subnets), and suppose both VLANs are configured on the very same physical
Ethernet interface (how you do that it depends by the router), the same is
valid if you use separate Ethernet interfaces on your Router, each one
carrying just one VLAN (in any case outgoing packets originating from VLAN
10 are tagged leaving the interface going to your switch and, conversly,
incoming VLAN 10 tagged packets are accepted on the very same interface
reaching the Router VLAN IP interface from the Switch...the same is valid
for VLAN 20)...well...in this case your switch needs that the uplink
interface (or interfaces) to the router is a tagged member of both VLAN 10
and 20. That is...now you can have, access side connected to your Aruba
switch, a VLAN unaware host connected to a port which is an untagged member
of VLAN 10 or 20 (not both) or you can have an aware VLAN host (you set a
VLAN id explicitly, say 10 or 20) connected to a port which is a tagged
member on the same VLAN id of the host (no VLAN ids match, no traffic)...in
both cases...that host, properly IP addressed, should be able to - at least
- ping its gateway and hosts in the very same VLAN (Subnet). That is the
basic to start with.
It's just one among some possible scenarios.
Nobody will force you proceeding by tagging or untagging a particular port
(access use, uplink use), I mean that it could also work by using - say -
different uplink ports each one untagged respectively on VLAN 10 or 20 but,
you know, why not to use a single link uplink carrying multiple VLANs at
once instead (Cisco guys will call it "a trunk port" while for HP ProCurve
guys the term "trunk" is used to represent a links aggregation which is not
necessarily related to VLAN tagging, even if a links aggregation interface
acts quite like a physical port in terms of VLAN tagging capabilities):
each port can carry (send outgoing/accept received) untagged packets (so no
tag, only one choice here) and eventually packets with various tags (many
tags)...so it's up to you to decide the way a packet flows along its
journey through your network (considering that internally to a switch
packets travel with tags).