IP Routing
6-11
8000-A2-GB21-20
November 1997
97-15473-02
Router
155.1.3.1
DSL Card*
s1c
RTU 1*
135.1.3.3
155.1.3.4
ES1
s1d
RTU 2*
135.1.3.4
155.1.3.5
ES2
Packet Flow
e1a
155.1.2.1
NSP
155.1.2.2
Host/Net
1) 155.1.3.4
2) 155.1.3.5
Subnet Mask
255.255.255.255
255.255.255.255
Next-Hop Address
155.1.3.1
155.1.3.1
S/D (Source/Destination)
src (source)
src (source)
Partial DSL Routing Table
*If DSL card is an 8540 DSL card,
associated RTU will not have an IP address.
Upstream packets from ES1 (and ES2) are sent to 155.1.3.1, where in turn the
router would forward them to the NSP. Downstream packets from the NSP are
sent to ES2.
For upstream packets only (i.e., packets arriving over the DSL ports), the order of
routing precedence is:
1. Source host route
2. Source subnet route
3. Source network route
4. Destination host route
5. Destination subnet route
6. Destination network route
7. Default route
NOTE:
When using source routing, do not use the default route.