Trocha teorie a možné programy pro použití na TCPIP
| Vrstva síťového rozhraní | Síťová vrstva | Transportní | Aplikační |
| Vzhledem k ISO/OSI modelu: 1,2 | 3 | 4 | 5,6,7 |
| arp,arping, ethtool, mii-tool | ping, route, ifconfig,traceroute ping6,ip,traceroute6 win(netstat,route,ipconfig,tracert) |
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| iptables,etables | |||
| tcpdump, wireshark,nmap | |||
Příklady použítí:
arp – vypíše dynamickou tabulku MAC adress a jejich vztahu k IP adresam (arp -n)
ucitel@VYT3:~$ arp -n Adresa HWtyp HWadresa Příznaky Maska Rozhraní 192.168.10.24 (nekompletní) eth0 192.168.10.5 (nekompletní) eth0 192.168.10.33 ether 00:14:22:41:d6:b7 C eth0 192.168.10.14 ether 00:11:43:1e:cc:f3 C eth0
příkaz arping a jeho použití
ucitel@VYT3:~$ sudo arping -I eth1 -c 5 192.168.1.1 ARPING 192.168.1.1 from 192.168.1.50 eth1 Unicast reply from 192.168.1.1 [46:BD:F5:9F:57:0D] 1.249ms Unicast reply from 192.168.1.1 [46:BD:F5:9F:57:0D] 0.770ms Unicast reply from 192.168.1.1 [46:BD:F5:9F:57:0D] 0.815ms Unicast reply from 192.168.1.1 [46:BD:F5:9F:57:0D] 0.793ms Sent 4 probes (1 broadcast(s)) Received 4 response(s)
v případě nedostupnosti nebo unknow (nekompletní) stavu protější hosta je nutné řešit tuto problematiku řešením odstranění problému kabeláže nebo rychlosti ( cts/rts, flow-control, speed, Half/Full duplex, rozpojení kabeláže ) možno použití příkazu „ethtools“ nebo „miitools“
manipulace s rychlostmi a stavem síťového rozhraní
ucitel@VYT3:~$ sudo mii-tool eth0: negotiated 1000baseT-FD flow-control, link ok eth1: negotiated 100baseTx-FD, link ok
nebo ethtool
ucitel@VYT3:~$ sudo ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Supported pause frame use: No Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Half 1000baseT/Full Advertised pause frame use: Symmetric Advertised auto-negotiation: Yes Speed: 1000Mb/s Duplex: Full Port: Twisted Pair PHYAD: 1 Transceiver: internal Auto-negotiation: on MDI-X: Unknown Supports Wake-on: g Wake-on: g Current message level: 0x000000ff (255) drv probe link timer ifdown ifup rx_err tx_err Link detected: yes
důležité také „dmesg“ pokud se stav rozhraní mění v průběhu doby je dobré se soustředit na kabeláž, nebo síťový adaptér
ucitel@VYT3:~$ dmesg |grep eth [ 0.316935] i2c-core: driver [aat2870] using legacy suspend method [ 0.316940] i2c-core: driver [aat2870] using legacy resume method [ 51.494423] 8139too 0000:05:0a.0: eth0: RealTek RTL8139 at 0x1000, 00:e0:7d:8c:fc:b2, IRQ 21 [ 51.584316] tg3 0000:05:02.0: eth1: Tigon3 [partno(BCM95782A50) rev 3003] (PCI:33MHz:32-bit) MAC address 00:11:85:18:ca:0e [ 51.584325] tg3 0000:05:02.0: eth1: attached PHY is 5705 (10/100/1000Base-T Ethernet) (WireSpeed[0], EEE[0]) [ 51.584331] tg3 0000:05:02.0: eth1: RXcsums[1] LinkChgREG[0] MIirq[0] ASF[0] TSOcap[1] [ 51.584339] tg3 0000:05:02.0: eth1: dma_rwctrl[763f0000] dma_mask[64-bit] [ 57.705968] ADDRCONF(NETDEV_UP): eth0: link is not ready [ 57.705978] ADDRCONF(NETDEV_UP): eth1: link is not ready [ 62.285071] udevd[681]: renamed network interface eth0 to rename2 [ 62.315383] udevd[656]: renamed network interface eth1 to eth0 [ 62.349023] udevd[681]: renamed network interface rename2 to eth1 [ 65.394058] ADDRCONF(NETDEV_UP): eth0: link is not ready [ 68.256338] tg3 0000:05:02.0: eth0: Link is up at 1000 Mbps, full duplex [ 68.256344] tg3 0000:05:02.0: eth0: Flow control is on for TX and on for RX [ 68.256496] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready [ 68.269123] 8139too 0000:05:0a.0: eth1: link up, 100Mbps, full-duplex, lpa 0xC5E1 [ 2475.377667] tg3 0000:05:02.0: eth0: Link is down [ 2501.783243] tg3 0000:05:02.0: eth0: Link is up at 1000 Mbps, full duplex [ 2501.783249] tg3 0000:05:02.0: eth0: Flow control is on for TX and on for RX