En el trabajo se compro unos cables USB a RS232 chinos, no tienen ninguna marca. Y bueno al momento de conectarlo los drivers que trajo en un CD no funcionaban.
El dispositivo se veia como:
USB2.0-ser!
Leyendo en un blog encontré la solución instalando el driver de este comprimido:
https://drive.google.com/file/d/0B-VOsF2QjPcuTTM3QXRlNU95WDA/view?usp=sharing
Santo remedio, funciono perfecto con un CISCO.
viernes, 30 de junio de 2017
Aislantes termico naturales
Muy interesante, alternativas de aislante térmico para el hogar.
Una comparativa del aislante termico de muros hecho en Argentina:
Una comparativa del aislante termico de muros hecho en Argentina:
¿Cómo se hizo el estudio?
Para cada uno de los sistemas constructivos se calculó teóricamente la Transmitancia Térmica (K) mediante la utilización de un programa de simulación numérica que analiza el fenómeno de transmisión de calor en geometría bidimensional. Como segundo paso, se aislaron dichos sistemas constructivos mediante el agregado de un material aislante térmico convencional de conductividad térmica media igual a 0,040 W/m.K, incorporando 3 pulgadas (aproximadamente 7,5cm) en el techo y 2 pulgadas (aproximadamente 5cm) en los muros. Con esta metodología se obtuvieron para cada caso las respectivas Transmitancias Térmicas, cuyos resultados se detallan en la Tabla 1.
Tabla 1: Transmitancia térmica de muros y techos evaluados
Sistemas Constructivos
|
Transmitancia Térmica [W/m²K] del muro sin aislación
|
Transmitancia Térmica [W/m²K] del muro con aislación
|
| Muro de ladrillo hueco del 12 |
2,10
|
0,52
|
| Muro de ladrillo hueco del 18 |
1,53
|
0,47
|
| Muro de bloques de hormigón |
2,46
|
0,53
|
| Techo de cubierta metálica |
2,50
|
0,50
|
| Techo de losa de hormigón armado |
2,27
|
0,41
|
Cuadro comparativo
| Descripción del Muro | Espesor (cm) | Transmitáncia Térmica k | |
| w/(m².°C) | kcal/(m².hora.°C) | ||
| Muro de Ladrillos HCCA | 20 | 0,54 | 0,47 |
| Muro de Ladrillos HCCA | 17,5 | 0,62 | 0,54 |
| Muro de Ladrillos HCCA | 15 | 0,70 | 0,60 |
| Muro doble LH12 + cámara de aire 2 cm + LH12 revocado en ambas caras 2 cm | 30 | 0,91 | 0,78 |
| Muro doble LH12 + cámara de aire 2 cm + LH12 revocado en ambas caras 2 cm | 30 | 1,01 | 0,87 |
| Muro de ladrillo cerámico portante de 18 cm revocado en ambas caras 1 cm | 20 | 1,31 | 1,13 |
| Muro de ladrillo cerámico portante de 12 cm revocado en ambas caras 1 cm | 15 | 1,55 | 1,33 |
| Muro de ladrillo hueco 12 cm revocado en ambas caras 1,5 cm | 15 | 1,74 | 1,50 |
| Muro de ladrillo común de 12 cm revocado en ambas caras | 15 | 2,68 | 2,30 |
sábado, 29 de abril de 2017
Firewall para mikrotik
This script has basic rules to protect your router and avoid some unnecessary forwarding traffic. Pay attention for all comments before apply each DROP rules.
HANDS ON! First we need to create our ADDRESS LIST with all IPs we will use most times
Below you need to change x.x.x.x/x for your technical subnet. This subnet will have full access to the router.
/ip firewall address-list add address=x.x.x.x/x disabled=no list=support
Below we have the bogon list.
/ip firewall address-list add address=0.0.0.0/8 comment="Self-Identification [RFC 3330]" disabled=no list=bogons add address=10.0.0.0/8 comment="Private[RFC 1918] - CLASS A # Check if you need this subnet before enable it"\ disabled=yes list=bogons add address=127.0.0.0/8 comment="Loopback [RFC 3330]" disabled=no list=bogons add address=169.254.0.0/16 comment="Link Local [RFC 3330]" disabled=no list=bogons add address=172.16.0.0/12 comment="Private[RFC 1918] - CLASS B # Check if you need this subnet before enable it"\ disabled=yes list=bogons add address=192.168.0.0/16 comment="Private[RFC 1918] - CLASS C # Check if you need this subnet before enable it"\ disabled=yes list=bogons add address=192.0.2.0/24 comment="Reserved - IANA - TestNet1" disabled=no list=bogons add address=192.88.99.0/24 comment="6to4 Relay Anycast [RFC 3068]" disabled=no list=bogons add address=198.18.0.0/15 comment="NIDB Testing" disabled=no list=bogons add address=198.51.100.0/24 comment="Reserved - IANA - TestNet2" disabled=no list=bogons add address=203.0.113.0/24 comment="Reserved - IANA - TestNet3" disabled=no list=bogons add address=224.0.0.0/4 comment="MC, Class D, IANA # Check if you need this subnet before enable it"\ disabled=yes list=bogons
Now we have protection against: SynFlood, ICMP Flood, Port Scan, Email Spam and much more. For more information read the comments.
/ip firewall filter add action=add-src-to-address-list address-list=Syn_Flooder address-list-timeout=30m chain=input \ comment="Add Syn Flood IP to the list" connection-limit=30,32 disabled=no protocol=tcp tcp-flags=syn add action=drop chain=input comment="Drop to syn flood list" disabled=no src-address-list=Syn_Flooder add action=add-src-to-address-list address-list=Port_Scanner address-list-timeout=1w chain=input comment="Port Scanner Detect"\ disabled=no protocol=tcp psd=21,3s,3,1 add action=drop chain=input comment="Drop to port scan list" disabled=no src-address-list=Port_Scanner add action=jump chain=input comment="Jump for icmp input flow" disabled=no jump-target=ICMP protocol=icmp add action=drop chain=input\ comment="Block all access to the winbox - except to support list # DO NOT ENABLE THIS RULE BEFORE ADD YOUR SUBNET IN THE SUPPORT ADDRESS LIST"\ disabled=yes dst-port=8291 protocol=tcp src-address-list=!support add action=jump chain=forward comment="Jump for icmp forward flow" disabled=no jump-target=ICMP protocol=icmp add action=drop chain=forward comment="Drop to bogon list" disabled=no dst-address-list=bogons add action=add-src-to-address-list address-list=spammers address-list-timeout=3h chain=forward comment="Add Spammers to the list for 3 hours"\ connection-limit=30,32 disabled=no dst-port=25,587 limit=30/1m,0 protocol=tcp add action=drop chain=forward comment="Avoid spammers action" disabled=no dst-port=25,587 protocol=tcp src-address-list=spammers add action=accept chain=input comment="Accept DNS - UDP" disabled=no port=53 protocol=udp add action=accept chain=input comment="Accept DNS - TCP" disabled=no port=53 protocol=tcp add action=accept chain=input comment="Accept to established connections" connection-state=established\ disabled=no add action=accept chain=input comment="Accept to related connections" connection-state=related disabled=no add action=accept chain=input comment="Full access to SUPPORT address list" disabled=no src-address-list=support add action=drop chain=input comment="Drop anything else! # DO NOT ENABLE THIS RULE BEFORE YOU MAKE SURE ABOUT ALL ACCEPT RULES YOU NEED"\ disabled=yes add action=accept chain=ICMP comment="Echo request - Avoiding Ping Flood" disabled=no icmp-options=8:0 limit=1,5 protocol=icmp add action=accept chain=ICMP comment="Echo reply" disabled=no icmp-options=0:0 protocol=icmp add action=accept chain=ICMP comment="Time Exceeded" disabled=no icmp-options=11:0 protocol=icmp add action=accept chain=ICMP comment="Destination unreachable" disabled=no icmp-options=3:0-1 protocol=icmp add action=accept chain=ICMP comment=PMTUD disabled=no icmp-options=3:4 protocol=icmp add action=drop chain=ICMP comment="Drop to the other ICMPs" disabled=no protocol=icmp add action=jump chain=output comment="Jump for icmp output" disabled=no jump-target=ICMP protocol=icmp
I think this is basic. You can add or remove anything else according to your needs. I hope it helps!
By Guilherme Ramires
Fuente:
https://wiki.mikrotik.com/wiki/Basic_universal_firewall_script
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