访问列表防御
1.创建访问列表
access-list 101 deny udp any any eq 1434
access-list 101 permit ip any any
2.匹配访问列表和数据包长度
class-map match-all slammer_worm
match access-group 101
match packet length min 404 max 404
3.丢弃所匹配的数据包
policy-map drop-slammer-worm
class slammer_worm
police 1000000 31250 31250 conform-action drop exceed-action drop violate-action drop
NBAR
1. Create custom protocol
ip nbar port-map custom-01 udp 1434
2. Create class-map
class-map match-all slammer_worm
match protocol custom-01
match packet length min 404 max 404
3. Use class-based policing to drop the matching packets at the ingress interface
policy-map drop-slammer-worm
class slammer_worm
police 1000000 31250 31250 conform-action drop exceed-action drop violate-action drop
NetFlow
Router# config t
Router# (config) interface serial 0/1
Router#(config-if) ip route-cache flow
Router#(config-if) exit
Router#(config) exit
Router#
输出统计表
Router# (config) ip flow-export 192.168.155.1 700
To view NetFlow statistics for port 1434:
Router# show ip cache flow | include 059A
CAR
Router# (config) access-list 150 deny udp any any eq 1434
Router# (config) access-list 150 permit ip any any
Router# (config) interface fastEthernet 0/0
Router# (config-if) rate-limit input access-group rate-limit 150 8000 1500 20000 conform-action drop exceed-action drop
Router# (config-if) exit
Router# (config) exit
Router#
ACL补充
access-list 115 deny udp any any eq 1434
access-list 115 permit ip any any
int
ip access-group 115 in
ip access-group 115 out
注意，如果你想追踪来源，最好使用netflow，而不要使用log。
病毒发送大量随机地址，如果路由器接口使用了“ICMP unreachable”命令的话，对这些大量的无效地址响应将导致路由器性能下降。因此，推荐使用以下命令：
Router(config)# interface
Router(if-config)# no ip unreachables
ICMP unreachable 的补充
如果某些情况，如IP 隧道（tunnel）必须使用ICMP unreachable 命令，则推荐使用
Router(config)# ip icmp rate-limit unreachable
6500 上防御
set security acl ip WORM deny udp any eq 1434 any
set security acl ip WORM deny udp any any eq 1434
set security acl ip WORM permit any
commit security acl WORM
set security acl map WORM
查看
show security acl info all
CatOS SUPII 和 MLS
CatOS SUPII 和 MLS
源码:
switch (enable) sh mls statistics entry ip
Last Used
Destination IP Source IP Prot DstPrt SrcPrt Stat-Pkts Stat-Bytes
10.81.176.91 172.16.34.35 UDP 1434 2776 0 0 172.31.171.82 172.16.34.35 UDP 1434 2776 0 0 168.192.57.204 172.16.188.61 UDP 1434 3460 1 404
172.17.136.55 172.16.34.135 UDP 1434 2917 0 0
从上面的显示我们可以发现，MLS可以帮助我们找到内部受感染主机
PIX
access-list acl_out permit udp any host eq 1434或者conduit permit udp any any eq 1434