Here is a quick background on what has become a terribly pervasive issue for us:
We have set up a remote site, connecting our corporate office to the site via VPN tunnel. The remote site has two outside interfaces, only one of which is up at any given time (for redundancy). What we are seeing is constant packet drops (maybe 60% of our packets are successfully transmitted, and outages can appear randomly and occur for several minutes).
We can connect to either ISP's gateway router, and have no issues with outside connectivity. Since both ISPs exhibit the same behavior, and are on different drops entirely, and since we have 100% success sending packets from the ISP's equipment, I do not believe the ISP is the issue.
What we have noticed in analyzing the traffic is a plethora of entries in the capture that look like this:
802.1Q vlan#1 P0 169.254.6.41.42388 > 169.254.255.255.42388: udp 46 Drop-reason: (sp-security-failed) Slowpath security checks failed
When viewing the results of show int, we see the following:
380358 switch ingress policy drops
The running-config is as follows:
ASA Version 8.2(5)
!
hostname HOST
enable password *** encrypted
passwd *** encrypted
names
!
interface Ethernet0/0
switchport access vlan 2
!
interface Ethernet0/1
switchport access vlan 3
!
interface Ethernet0/2
!
interface Ethernet0/3
!
interface Ethernet0/4
!
interface Ethernet0/5
!
interface Ethernet0/6
!
interface Ethernet0/7
!
interface Vlan1
nameif inside
security-level 100
ip address 192.168.9.254 255.255.255.0
!
interface Vlan2
nameif outside
security-level 0
ip address *.*.*.* 255.255.255.248
!
interface Vlan3
no forward interface Vlan2
nameif backupISP
security-level 0
ip address *.*.*.* 255.255.252.0
!
ftp mode passive
clock timezone CST -6
clock summer-time CDT recurring
access-list outside_cryptomap extended permit ip 192.168.9.0 255.255.255.0 192.1
68.0.0 255.255.255.0
access-list outside_cryptomap extended permit ip 192.168.9.0 255.255.255.0 192.1
68.2.0 255.255.255.0
access-list outside_cryptomap extended permit ip 192.168.9.0 255.255.255.0 10.10
.0.0 255.255.0.0
access-list nonat extended permit ip 192.168.9.0 255.255.255.0 192.168.0.0 255.2
55.255.0
access-list nonat extended permit ip 192.168.9.0 255.255.255.0 192.168.2.0 255.2
55.255.0
access-list nonat extended permit ip 192.168.9.0 255.255.255.0 10.10.0.0 255.255
.0.0
pager lines 24
logging enable
logging asdm warnings
mtu inside 1500
mtu outside 1500
mtu backupISP 1500
icmp unreachable rate-limit 1 burst-size 1
asdm image disk0:/asdm-722.bin
no asdm history enable
arp timeout 14400
global (outside) 1 interface
global (backupISP) 1 interface
nat (inside) 0 access-list nonat
nat (inside) 1 0.0.0.0 0.0.0.0
route outside 0.0.0.0 0.0.0.0 *.*.*.* 1
route backupISP 0.0.0.0 0.0.0.0 *.*.*.* 2
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00
timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute
timeout tcp-proxy-reassembly 0:01:00
timeout floating-conn 0:00:00
dynamic-access-policy-record DfltAccessPolicy
http server enable
http 192.168.9.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec transform-set ESP_3DES_SHA esp-3des esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-SHA esp-aes esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-MD5 esp-aes esp-md5-hmac
crypto ipsec transform-set ESP-AES-192-SHA esp-aes-192 esp-sha-hmac
crypto ipsec transform-set ESP-AES-192-MD5 esp-aes-192 esp-md5-hmac
crypto ipsec transform-set ESP-AES-256-SHA esp-aes-256 esp-sha-hmac
crypto ipsec transform-set ESP-AES-256-MD5 esp-aes-256 esp-md5-hmac
crypto ipsec transform-set ESP-AES-128-SHA-TRANS esp-aes esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-SHA-TRANS mode transport
crypto ipsec transform-set ESP-AES-128-MD5-TRANS esp-aes esp-md5-hmac
crypto ipsec transform-set ESP-AES-128-MD5-TRANS mode transport
crypto ipsec transform-set ESP-AES-192-SHA-TRANS esp-aes-192 esp-sha-hmac
crypto ipsec transform-set ESP-AES-192-SHA-TRANS mode transport
crypto ipsec transform-set ESP-AES-192-MD5-TRANS esp-aes-192 esp-md5-hmac
crypto ipsec transform-set ESP-AES-192-MD5-TRANS mode transport
crypto ipsec transform-set ESP-AES-256-SHA-TRANS esp-aes-256 esp-sha-hmac
crypto ipsec transform-set ESP-AES-256-SHA-TRANS mode transport
crypto ipsec transform-set ESP-AES-256-MD5-TRANS esp-aes-256 esp-md5-hmac
crypto ipsec transform-set ESP-AES-256-MD5-TRANS mode transport
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-3DES-SHA-TRANS esp-3des esp-sha-hmac
crypto ipsec transform-set ESP-3DES-SHA-TRANS mode transport
crypto ipsec transform-set ESP-3DES-MD5-TRANS esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-3DES-MD5-TRANS mode transport
crypto ipsec transform-set ESP-DES-SHA esp-des esp-sha-hmac
crypto ipsec transform-set ESP-DES-MD5 esp-des esp-md5-hmac
crypto ipsec transform-set ESP-DES-SHA-TRANS esp-des esp-sha-hmac
crypto ipsec transform-set ESP-DES-SHA-TRANS mode transport
crypto ipsec transform-set ESP-DES-MD5-TRANS esp-des esp-md5-hmac
crypto ipsec transform-set ESP-DES-MD5-TRANS mode transport
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
crypto map mymap 1 match address outside_cryptomap
crypto map mymap 1 set peer *.*.*.*
crypto map mymap 1 set transform-set ESP_3DES_SHA
crypto map mymap interface outside
crypto map mymap interface backupISP
crypto isakmp enable outside
crypto isakmp enable backupISP
crypto isakmp policy 10
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 86400
telnet 0.0.0.0 0.0.0.0 inside
telnet timeout 5
ssh timeout 30
console timeout 0
management-access inside
dhcpd auto_config outside
!
dhcpd address 192.168.9.100-192.168.9.200 inside
dhcpd dns 192.168.9.2 interface inside
dhcpd enable inside
!
threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
ssl encryption 3des-sha1 aes128-sha1 aes256-sha1 rc4-sha1
webvpn
tunnel-group *.*.*.* type ipsec-l2l
tunnel-group *.*.*.* ipsec-attributes
pre-shared-key *****
!
class-map inspection_default
match default-inspection-traffic
!
!
policy-map type inspect dns preset_dns_map
parameters
message-length maximum client auto
message-length maximum 512
policy-map global_policy
class inspection_default
inspect dns preset_dns_map
inspect ftp
inspect h323 h225
inspect h323 ras
inspect rsh
inspect rtsp
inspect esmtp
inspect sqlnet
inspect skinny
inspect sunrpc
inspect xdmcp
inspect sip
inspect netbios
inspect tftp
inspect ip-options
!
service-policy global_policy global
prompt hostname context
no call-home reporting anonymous
Crypto checksum:***
: end
Any thoughts on what could be causing us to lose so many packets? Any help is appreciated. Thanks.
