Troubleshooting guide

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Cisco Wide Area Application Services Configuration Guide
OL-26579-01
Chapter 1 Planning Your WAAS Network
Supported Methods of Traffic Redirection
This traffic redirection does not use tunneling; the full original quadruple (source IP address, source port
number, destination IP address, and destination port number) of the TCP traffic is preserved end to end.
The original payload of the TCP traffic is not preserved end to end because the primary function of
WAAS is to accelerate WAN traffic by reducing the data that is transferred across the WAN. This change
in payload can potentially impact features on the router (which is performing the WCCP or PBR
redirection) that needs to see the actual payload to perform its operation (for example, NBAR). For more
information on this topic, see the “WAAS and Cisco IOS Interoperability” section on page 1-11.
Using WCCP or PBR at both ends with no tunneling requires that traffic is intercepted and redirected
not only in the near-end router but also at the far-end router, which requires four interception points as
opposed to two interception points in a tunnel-based mode.
You can enable packet redirection on either an outbound interface or inbound interface of a
WCCP-enabled router. The terms outbound and inbound are defined from the perspective of the
interface. Inbound redirection specifies that traffic should be redirected as it is being received on a given
interface. Outbound redirection specifies that traffic should be redirected as it is leaving a given
interface.
If you are deploying WAN optimization in your WAAS network, then you must configure the router and
WAE for WCCP Version 2 and the TCP promiscuous mode service (WCCP Version 2 services 61 and
62 by default).
Note Services 61 and 62 are always enabled together when configuring TCP promiscuous on the WAE.
Services 61 and 62 must be defined and configured separately when configuring TCP promiscuous on
the network device (router, switch, or other). Service 61 distributes traffic by source IP address, and
service 62 distributes traffic by destination IP address. The service IDs are configurable; 61 and 62 are
the defaults.
The TCP promiscuous mode service intercepts all TCP traffic that is destined for any TCP port and
transparently redirects it to the WAE. The WCCP-enabled router uses service IDs 61 and 62 to access
this service. The service IDs used on the router must match those on the WAE if different service IDs
than the defaults are configured.
Table 1-1 Router Interfaces for WCCP or PBR Traffic Redirection to WAEs
Router
interface Description
Edge-Router1
A Edge LAN interface (ingress interface) that performs redirection on the outbound traffic.
B Tertiary interface (separate physical interface) or a subinterface off of the LAN port on Edge-Router1. Used to
attach Edge-WAE1 to Edge-Router1 in the branch office.
C Edge WAN interface (egress interface) on Edge-Router1 that performs redirection on the inbound traffic.
Core-Router1
D Core LAN interface (ingress interface) that performs redirection on outbound traffic.
E Tertiary interface or subinterface off of the LAN port on Core-Router1. Used to attach Core-WAE1 to
Core-Router1 in the data center.
F Core WAN interface (egress interface) on Core-Router1 that performs redirection on the inbound traffic.