tcp-ping-port
A simple TCP ping utility to ping a port of an IP or domain.
Table of contents
Benefits
Following are the pros and cons of this package compared to the regular ping
Pros
- Can be used with Amazon Lambda functions and Aazure functions.
Regularping
uses ICMP protocol which is not permitted by AWS/Azure functions - TCP packets have higher priorty than ICMP packets
- It can ping a particular port
- It can work even if ICMP is disabled
Cons
-
Higher data usage
Protocol Send (B)) Receive (B) Total (B) Data saving TCP 228 126 354 0% ICMP 98 98 196 45% The numbers are based on data reported by Wireshark
#### TCP Ping
No. Time Source Destination Protocol Length Info 1 0.000000 x.x.x.x y.y.y.y DNS 70 Standard query 0xfe55 A google.com 2 0.000393 y.y.y.y x.x.x.x DNS 86 Standard query response 0xfe55 A google.com A 172.217.165.14 3 0.001364 x.x.x.x 172.217.165.14 TCP 66 49985 → 80 [SYN] Seq=0 Win=64240 Len=0 MSS=1460 WS=256 SACK_PERM=1 4 0.012339 172.217.165.14 x.x.x.x TCP 66 80 → 49985 [SYN, ACK] Seq=0 Ack=1 Win=65535 Len=0 MSS=1430 SACK_PERM=1 WS=256 5 0.012412 x.x.x.x 172.217.165.14 TCP 54 49985 → 80 [ACK] Seq=1 Ack=1 Win=262912 Len=0 6 0.013110 x.x.x.x 172.217.165.14 TCP 54 49985 → 80 [FIN, ACK] Seq=1 Ack=1 Win=262912 Len=0 7 0.024927 172.217.165.14 x.x.x.x TCP 60 80 → 49985 [FIN, ACK] Seq=1 Ack=2 Win=65536 Len=0 8 0.024987 x.x.x.x 172.217.165.14 TCP 54 49985 → 80 [ACK] Seq=2 Ack=2 Win=262912 Len=0 #### ICMP ping
No. Time Source Destination Protocol Length Info 1 0.000000 x.x.x.x y.y.y.y DNS 70 Standard query 0xff9e A google.com 2 0.003286 y.y.y.y x.x.x.x DNS 86 Standard query response 0xff9e A google.com A 172.217.165.14 3 0.040291 x.x.x.x 172.217.165.14 ICMP 98 Echo (ping) request id=0x0279, seq=1/256, ttl=128 (reply in 6) 4 0.064258 172.217.165.14 x.x.x.x ICMP 98 Echo (ping) reply id=0x0279, seq=1/256, ttl=112 (request in 5) NOTE: The first 2 DNS resolution calls are same in both cases for IPv4 and are not included in the total data usagage.
Installation
$ npm install tcp-ping-port --save
How to use
Simple examples
const tcpPingPort =
With additional options
const tcpPingPort = const dns = const options = socketTimeout: 11000 dnsTimeout: 10000 dnsServers: '8.8.8.8' // google DNS
Dependencies
dns-fast-resolver
- to resolve multiple domains at the same time and to handle any errors while resolving the domain name. Also, to skip the whole dns resolution if host name is an IP address.lodash
maketype
API
tcpPingPort(hostname[, port, options, resolver])
Attemps to open and close TCP connection
-
hostname
<string>
Host name or an IP address to try to connect to -
port
<number>
Port number -
options
<Object>
Socket and Resolver options- socketTimeout
<integer>
Number of miliseconds to wait before the resolving request is canceled. Default value 4000 (4s). - dnsTimeout
<integer>
Number of miliseconds to wait before the resolving request is canceled. Default value 4000 (4s).
Usefull for rare cases when hostnames may need more than default 4 seconds to be resolved. - dnsServers
<string[]>
Array of RFC 5952 formatted addresses. (Example:['4.4.4.4', '[2001:4860:4860::8888]', '4.4.4.4:1053', '[2001:4860:4860::8888]:1053']
)
- socketTimeout
-
returns
<Promise>
Promise that will return online status ofhost
True
- when host is online and TCP connection is successfully opened and closedFalse
- when host name is not resolved or it failed to open a TCP connection
Testing
Run all tests
$ npm test
Run ping "google.com:80"
test
$ npm run unit-test -- --grep "google.com:80"