Host 2 queries for printers
The following procedure depicts a service process for mDNS queries for a wireless printer in the form of an
example.
Procedure
1.
Host 2 sends an mDNS query for printers.
2.
There is no inbound filter in VLAN 2 of Switch 3 therefore it receives the query.
3.
Switch 3 checks the outbound filter in VLAN 2. As there is no specific outbound filter the default action is
permit all
.
4.
Switch 3 floods the query in VLAN 2 (except the source port.)
5.
Switch 1 receives the query and check the inbound filters. Permit for the instance name, Host 2, allows the
packet on VLAN 2.
6.
Switch 1 checks the outbound filter for VLAN 2. As there is no specific filter and global filter is
permit all
, it
will flood the packet in VLAN 2 (except the source port.)
7.
Switch 1 checks the reflection status. Reflection is enabled on VLAN 2 and VLAN 3. Since VLAN 2 is an
incoming VLAN, it will not pass the reflection on VLAN 2.
8.
Switch 1 checks the outbound filters on VLAN 3. There is no rule to deny Host 2 query and the global filter is
set to
permit all
so it will forward the packet to VLAN 3.
9.
Switch 2 receives the service and checks for any inbound and outbound filters in VLAN 3.
10.
There is no specific inbound and outbound filter in VLAN 3 therefore it will flood the query in VLAN 3 (except
the source port.)
11.
Reflection is not enabled in Switch 2 therefore it will not pass any further reflection.
12.
Wireless printer 2 responses to the query and switch 2 does not have any inbound and outbound filters
therefore it will flood the response to VLAN 3 (except the source port.)
13.
Switch 1 receives the packet as there are no inbound filters in VLAN 3. VLAN 3 has an outbound filter set to
deny wireless printer service. The service will not flood VLAN 3.
14.
Switch 1 checks the reflection status which is enabled in VLAN 2 and 3. Since the incoming VLAN is 3, the
packet will not forward to VLAN 3.
15.
Switch 1 checks the outbound filter in VLAN 2. As there is no specific filter, it will forward the response to
VLAN 2.
16.
Switch 3 receives the response on VLAN 2 as there is no inbound filter to deny this service.
17.
Switch 3 does not have any outbound filters in VLAN 2, so it will flood the response in VLAN 2 (except the
source port.)
18.
Host 2 receives the Wireless Printer 2 service response.
iPhone 1 queries for printers
The following depicts a service process for iPhone queries for a wireless printer in the form of an example .
1.
iPhone 1 sends an mDNS query for printers in switch 1 on VLAN 1.
2.
Switch 1 checks the inbound filter in VLAN 1. As there is no specific filters, it receives the query.
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Aruba 3810 / 5400R Multicast and Routing Guide for ArubaOS-
Switch 16.08