Cisco
防火牆和上行鏈路之間的封包遺失?
我的外部防火牆和 Internet 之間有一個中等複雜的網路拓撲,如下所示。
每隔一段時間——我還沒有找到一種模式——我們會出現很大程度的丟包,大約 25%。大多數時候它低於 0.5%。據我所知,唯一的共同點是所有丟棄的流量都通過從
vpn server
Cisco ASA 5505 到gateway router
Cisco 2901 的介面。編輯
除了純粹丟棄的數據包外,我還在查看響應時間。與停止一步的 ping 相比,
gateway router
任何來自vpn server
或fiber uplink
正在增加的流量正好增加 200 毫秒。由於高 ping 響應時間是 CPU 被最大化的常見指標,我檢查了
show process cpu
,但它只顯示了大約 40% 的使用率。有什麼想法嗎?
結束編輯
假設問題確實存在於 ASA 和 2901 之間的介面上,我清除了兩個設備上的介面統計資訊。
從那以後,我們經歷了幾次丟包增加的時期。介面統計數據如下,但從我的角度來看,沒有顯示任何異常 - 沒有格式錯誤或丟棄的數據包,介面重置等。雙工和速度設置匹配。
我錯過了什麼?所有這些硬體都在建設中,至少有 100 mbps 的連接。
網關路由器
show interfaces GigabitEthernet 0/0 GigabitEthernet0/0 is up, line protocol is up Hardware is CN Gigabit Ethernet, address is a493.4ccc.b218 (bia a493.4ccc.b218) Internet address is xx.xx.xx.105/28 MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec, reliability 255/255, txload 14/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full Duplex, 100Mbps, media type is RJ45 output flow-control is unsupported, input flow-control is unsupported ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:00, output 00:00:00, output hang never Last clearing of "show interface" counters 00:15:51 Input queue: 0/75/0/6427 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 511000 bits/sec, 401 packets/sec 5 minute output rate 5526000 bits/sec, 590 packets/sec 413812 packets input, 83711483 bytes, 0 no buffer Received 5 broadcasts (0 IP multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast, 0 pause input 600299 packets output, 695003736 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 unknown protocol drops 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 pause output 0 output buffer failures, 0 output buffers swapped out
VPN伺服器
show interface ethernet 0/1 Interface Ethernet0/1 "", is up, line protocol is up Hardware is 88E6095, BW 100 Mbps Auto-Duplex(Full-duplex), Auto-Speed(100 Mbps) Available but not configured via nameif MAC address 001e.f76a.a441, MTU not set IP address unassigned 215073 packets input, 247716476 bytes, 0 no buffer Received 7 broadcasts, 0 runts, 0 giants 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 0 L2 decode drops 39 switch ingress policy drops 148763 packets output, 21509818 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 babbles, 0 late collisions, 0 deferred 0 lost carrier, 0 no carrier 0 rate limit drops 0 switch egress policy drops
原來是5505 vpn伺服器上的一個壞介面。從那時起,我們重新連接,事情一直堅如磐石。