
When you have redundant [VPN](/vpn) connections to [AWS](/how-to-study-amazon-aws) using a Cisco [ASA](/asa), and you have configured [BGP](/bgp) routing, asymmetric [routing](/routing) will typically take place. Communication that is sent out via one tunnel is responded to via the other.

The ASA is configured to drop responses that arrive asymmetrically by default.

There are several solutions that have been successfully applied, although the best approach is to discuss your requirements with AWS staff.


BGP Asymmetric routing when using ASA with AWS

BGP - Multipath Attribute Prerequisites

BGP - Network Layer Reachability Information (NLRI)

BGP - Next Hop Address Tracking vs Route Dampening

BGP - Outbound Route Filtering

BGP - RRs vs confederations

BGP - TCP Peering Session Process

BGP - The BGP Table

BGP - The BGP table vs the Routing table

BGP - Why is MED non-transitive

BGP - aggregate-address command in action

BGP - aggregate-address default route

BGP - aggregate-address with a single subnet

BGP - bgp redistribute-internal command

BGP - definition of External BGP (eBGP)

BGP - definition of Internal BGP (iBGP)

BGP - eBGP loop prevention mechanism same AS number

BGP - eBGP peerings

BGP - iBGP full-mesh peering

BGP - iBGP split horizon rule

BGP - multicast routing

BGP - multipath in a DMVPN environment

BGP - multiprotocol BGP

BGP - network command with subnet mask

BGP - network vs redistribute commands

BGP - next-hop-self vs update source

BGP - preventing transit traffic

BGP - redistributing iBGP routes into an IGP

BGP - remove private AS

BGP - route maps and using the continue clause

BGP - transitive and non-transitive attributes

BGP - update-source command

BGP - using peer-groups with multiple outbound policies

BGP - using private ASNs with private IPs

BGP - using public IPs with private ASes

BGP - why is eBGP preferred over iBGP

BGP 4-Byte AS Number - Asdot notation

BGP 4-Byte AS Number - Asdot plus notation

BGP 4-Byte AS Number - Asplain notation

BGP 4-byte ASN Backward Compatibility

BGP AS Path Filtering and Manipulation

BGP AS Path

BGP AS number notation

BGP AS-Override Risks

BGP AS_PATH when using aggregate-address

BGP AS_SET and AS_CONFED_SET Deprecated

BGP AS_TRANS

BGP Advertised Routes and Outbound Policy Application

BGP Advertising a prefix

BGP Advertising a route using the Null0 exit interface

BGP Attributes - route map direction

BGP Authentication

BGP Auto-Summary Best Practices

BGP Cluster ID

BGP Confederation peerings

BGP Confederations

BGP Default local preference and its appearance in the BGP table

BGP Equal Cost Multipath AS_Path Attribute

BGP Equal cost multipath configuration syntax

BGP Equal cost multipath

BGP Extended Community

BGP ISPs prefixes advertised to enterprise edge routers

BGP Influence incoming traffic

BGP Load balancing

BGP MD5 Authentication

BGP Maximum Prefix Feature

BGP Maximum message size

BGP Origin AS Validation

BGP Originator ID

BGP PIC and its Relationship with BGP Attributes

BGP Path Selection Oldest Path

BGP RIB failure Administrative Distance

BGP RIB failure

BGP Routing Table Entry without Exit Interface

BGP Site of Origin (SoO) Community

BGP Standard Community

BGP Table Origin Code

BGP Update Groups

BGP Update Total Path Attribute Length field

BGP active and passive peers

BGP advertises only the best path by default

BGP advertising a default route

BGP aggregate-address

BGP and route tagging

BGP applying route maps to prefixes

BGP communities

BGP community propagation

BGP community types

BGP configuring authentication on an established BGP session

BGP dmzlink-bw feature

BGP eBGP next hop optimization

BGP hold timer

BGP how MED attribute is compared

BGP influence Outgoing Traffic

BGP installing a BGP-learned route into the routing table

BGP internal vs external

BGP multihop vs disable-connected-check

BGP neighbor activate command

BGP neighbor-group

BGP paths indicated in the show ip bgp command