ตะกร้า 0

ไฟร์วอลล์

ดูในมุมมอง ตาราง รายการ

รายการ 73-96 ของ 136

ตั้งค่าเรียงจากน้อยไปมาก
ต่อหน้า
  1. WatchGuard Firebox NV5

    WatchGuard Firebox NV5

    • Firewall (UDP 1518) N/A
    • VPN (UDP 1518) 200 Mbps
    • AntiVirus N/A
    • IPS (FUll Scan) N/A
    • UTM (Full Scan) N/A
    • Interfaces 3 x 1 Gb
    • I/O Interfaces 1 Serial / 1 USB
    • Concurrent connections 73,000
    • New connections per second 8,500
    • VLAN Support 10

     

    ขอใบเสนอราคาติดต่อฝ่ายขาย LINE: @monsterconnect

    Call Center 02-026-6664 Email: [email protected]

    ฿0.00
  2. KEMP LoadMaster VLM-3000 appliance. Includes 200 Mbps

    แบบ VM

    Virtual LoadMaster appliance, 3 Gbps, 4000 SSL TPS License. Support Required.

    ***ราคานี้รวม 1 Years Enterprise Plus Subscription for LoadMaster VLM-3000 แล้ว****

    ฿1.00
  3. KEMP LoadMaster LM-X3 appliance. Includes 3.4 Gbps

    แบบ Hardware Box

    LoadMaster LM-X3 hardware appliance. Includes 3.4 Gbps, 1700 SSL TPS (2K keys), 8x 1Gb Ports. Support Required.

    ***ราคานี้รวม 1 Years Enterprise Plus Subscription for LoadMaster LM-X3 แล้ว***

     

     

    ฿1.00
  4. KEMP LoadMaster LM-X15 appliance. Includes 15 Gbps

    แบบ Hardware Box

    LoadMaster LM-X15 hardware appliance. Includes 15 Gbps, 12,000 SSL TPS (2K keys), 16x 1Gb Ports + 4x 10Gb Ports, Redundant PSU, Redundant Disks. Support Required.

    ***ราคานี้รวม Subscription 1 Years Enterprise Plus  for LoadMaster LM-X15 แล้ว****

     

     

     

    ฿1.00
  5. 118

    M5100-AC-I-S with NBD KIT-SFR17010000021 สินค้าชุดนี้ประกอบด้วย ( Kit นี้สำหรับซื้อพร้อม Box เท่านั้น)
          
    IAM51S SFR-M5100-AC-I-S M5100-AC-I-S, SANGFOR Internet Access Management Standard Packs,  
    IOU1-S-1Y SFR-IOU1-S-1Y M5100-AC-I-S/M5000-AC-I,Software, SANGFOR URL Database 1Year License  
    STS-IAM51-S-1Y SFR-STS-IAM51-S-1Y Software and Technical Support Only, SANGFOR IAM5100,1Year  
    HNBDG-IAM51-S-1Y SFR-HNBD-IAM51S-1Y Next Business Day Delivey Hardware Support Only, SANGFOR IAM5100, 1Year
            
    ฿1.00
  6. M5000-AC-I-S,SANGFOR Internet Access Management Standard Packs,

    M5000-AC-I-S with NBD KIT-SFR17010000018 สินค้าชุดนี้ประกอบด้วย ( Kit นี้สำหรับซื้อพร้อม Box เท่านั้น)  
    IAM50S SFR-M5000-AC-I-S M5000-AC-I-S,SANGFOR Internet Access Management Standard Packs,  
    IOU0-1Y SFR-IOU0-1Y M5000-AC-I-S/M5000-AC-I,Software, SANGFOR URL Database 1Year License
            
    STS-IAM50-1Y SFR-STS-IAM50-1Y Software and Technical Support Only, SANGFOR IAM5000,1Year  
    HNBDG-IAM50-1Y SFR-HNBDG-IAM50-1Y Next Business Day Delivey Hardware Support Only, SANGFOR IAM5000, 1Year
            
    ฿1.00
  7. Arbor SP-7000

    Features Description
    Power Requirements Redundant, load sharing and auto-sensing 850W dual power supples; AC: 100-240 VAC, 50/60 Hz, 12/6 A; DC: -40 to -72 V, 28/14 A max
    Physical Dimensions Chassis: 2U rack height; Weight: 36.95 lbs (17.7 kg); Height: 3.45 inches (8.76 cm); Width: 17.14 inches (43.54 cm); Depth: 20 inches (50.8 cm); Standard 19 inches and 23 inches rack mountable
    Hard Drives Six 480 GB solid state drives configured for RAID 5
    Network Interfaces 2 x 1 GigE (SFP for copper, GigE SX, or GigE LX); or 8 x 1 GigE (SFP for copper, GigE SX, or GigE LX); or 2 x 10 GigE (SFP+ for SR or LR) and 4 x 1 GigE (SFP for copper, GigE SX, or GigE LX)
    Environmental Operating temperature: 41° to 104°F (5° to 44°C); Humidity (operating): 95%, non-condensing at temperatures of 73º to 104º F (23º to 40º C)
    Operating System ArbOS is Arbor’s proprietary, embedded operating system, based on Linux.
    Regulatory Compliance UL60950-1/CSA 60950-1; EN60950-1; IEC60950-1; CB Certificate & Report including all international deviations; SONCAP; EAC Mark; CE—Low Voltage Directive 2014/35/EU; KCC Mark, RoHS 2011/65/EU; Telcordia GR-63; ETSI EN 300 019; NEBS; ETSI EN 300 753; cULus mark; IC ICES-003 Class A; CE mark to EMC Directive, 2014/30/EU; EN55022, Class A; EN55024; EN61000-3-2; EN61000-3-3; CISPR 22, Class A, CISPR 24 Immunity; FCC 47 CFR Parts 15, Class A
    ฿1.00
  8. Imperva X2510

    WAF
    Troughput 500Mbps
    Interface 4x1G Copper + 2 optional module with 4x1G Copper OR 4x1G OR 2x10G SR/LR
    Max Network Segment 4 Bridge, 9 Proxy, Non-inline
    Inline Fail Open 4 bypass segments
    Deployment Mode Transparent Bridge (Layer 2), Reverse Proxy and Transparent Proxy (Layer 7) & Non-inline sniffer
    High Availability IMPVHA (Active/Active, Active/Passive), Fail open interfaces (bridge mode only), VRRP & STP and RSTP
    Appliance Type X2510
    ฿1.00
  9. Imperva X4510

    Imperva SecureSphere appliances provide superior performance and resiliency for demanding data center environments. With fail open interfaces, SecureSphere platforms offer fast and cost-effective fail over. Out-of-band management enhances security, while front panel status messages and network interfaces improve manageability. SecureSphere appliances deliver a scalable, reliable and flexible platform to power Imperva's web, database, and file security solutions.
     

    Main Features

    • File Firewall
    • security appliance
    • 8 ports
    • GigE
    • 2U
    • rack-mountable
     
    ฿1.00
  10. Imperva X8510

    WAF
    Troughput 5Gbps
    Interface 8x 1G Copper + 4x 10G SR/LR
    Max Network Segment 4x Bridge + 9x Proxy, Non-inline
    Inline Fail Open 4 bypass segments
    ฿1.00
  11. Radware 1Gbps

    WAF is a cloud firewall service that protects core website data and safeguards the security and availability of your site.

    Based on powerful Big Data cloud capabilities and underlying security, WAF provides protection against web-based attacks, including SQL injections, XSS, Malicious BOT, command execution vulnerabilities, and other common web attacks.

    Benefits

    Stability and Speed

    • Easy Deployment: No need to install additional software or to deploy extra hardware. You can access the product and secure your website within minutes

    • Shorter Response Time: Extremely short response time (milliseconds) for user requests

    • Improved Monitoring and Service Systems: Offers 24/7 network-wide smart monitoring and scheduling based on service quality

    Defense Capabilities

    • Centrally Defined Protection Rules: Nearly 1,000 protection rules, updated each day across all web applications by a dedicated defense team in order to protect from false positive rates

    • Patch Synchronization: Offers 0-day web vulnerability patches synchronized globally within 24 hours

    • Superior Defense: Comprehensive website security protection through precise access controls to provide powerful defense against web/flood attacks

    Big Data Security Analysis

    • Security Protection: Protects thousands of data sensitive websites against millions of web attacks

    • Global Synchronization: Collaborative defense captures new threats and globally synchronizes protection rules

    • Big Data Learning Models: WAF utilizes a big data learning model to reduce the rate of false positives

    Visibility

    • Real-time Metrics of Web Requests: Monitors requests that match your filter criteria and provides real-time metrics for improved visibility of your web traffic, which you can create using new rules and alerts

    Cost-effective

    • Monthly Package: Offers monthly subscription with different package versions and feature specifications that you can select depending on your requirements

    ฿1.00
  12. Radware 200Mbps

    WAF is a cloud firewall service that protects core website data and safeguards the security and availability of your site.

    Based on powerful Big Data cloud capabilities and underlying security, WAF provides protection against web-based attacks, including SQL injections, XSS, Malicious BOT, command execution vulnerabilities, and other common web attacks.

    Benefits

    Stability and Speed

    • Easy Deployment: No need to install additional software or to deploy extra hardware. You can access the product and secure your website within minutes

    • Shorter Response Time: Extremely short response time (milliseconds) for user requests

    • Improved Monitoring and Service Systems: Offers 24/7 network-wide smart monitoring and scheduling based on service quality

    Defense Capabilities

    • Centrally Defined Protection Rules: Nearly 1,000 protection rules, updated each day across all web applications by a dedicated defense team in order to protect from false positive rates

    • Patch Synchronization: Offers 0-day web vulnerability patches synchronized globally within 24 hours

    • Superior Defense: Comprehensive website security protection through precise access controls to provide powerful defense against web/flood attacks

    Big Data Security Analysis

    • Security Protection: Protects thousands of data sensitive websites against millions of web attacks

    • Global Synchronization: Collaborative defense captures new threats and globally synchronizes protection rules

    • Big Data Learning Models: WAF utilizes a big data learning model to reduce the rate of false positives

    Visibility

    • Real-time Metrics of Web Requests: Monitors requests that match your filter criteria and provides real-time metrics for improved visibility of your web traffic, which you can create using new rules and alerts

    Cost-effective

    • Monthly Package: Offers monthly subscription with different package versions and feature specifications that you can select depending on your requirements

    ฿1.00
  13. Barracuda 640

    Highly demanding enterprise networks require full-featured application delivery that optimizes application load balancing and performance while providing protection from an ever-expanding list of intrusions and attacks.

    Product Spotlight

    • • Multiport platform with fiber and copper network interfaces
    • • Advanced Layer 4 & Layer 7 load balancing
    • • SSL offloading & application acceleration
    • • Global Server Load Balancing for applicationdelivery across data centers
    • • Comprehensive attack protection and Data Loss Prevention
    ฿1.00
  14. Barracuda 540

    Highly demanding enterprise networks require full-featured application delivery that optimizes application load balancing and performance while providing protection from an ever-expanding list of intrusions and attacks.

    Product Spotlight

    • • Multiport platform with fiber and copper network interfaces
    • • Advanced Layer 4 & Layer 7 load balancing
    • • SSL offloading & application acceleration
    • • Global Server Load Balancing for applicationdelivery across data centers
    • • Comprehensive attack protection and Data Loss Prevention
    ฿1.00
  15. Barracuda 340

    Highly demanding enterprise networks require full-featured application delivery that optimizes application load balancing and performance while providing protection from an ever-expanding list of intrusions and attacks.

    Product Spotlight

    • • Multiport platform with fiber and copper network interfaces
    • • Advanced Layer 4 & Layer 7 load balancing
    • • SSL offloading & application acceleration
    • • Global Server Load Balancing for applicationdelivery across data centers
    • • Comprehensive attack protection and Data Loss Prevention
    ฿1.00
  16. Barracuda 240

    Highly demanding enterprise networks require full-featured application delivery that optimizes application load balancing and performance while providing protection from an ever-expanding list of intrusions and attacks.

    Product Spotlight

    • • Multiport platform with fiber and copper network interfaces
    • • Advanced Layer 4 & Layer 7 load balancing
    • • SSL offloading & application acceleration
    • • Global Server Load Balancing for applicationdelivery across data centers
    • • Comprehensive attack protection and Data Loss Prevention
    ฿1.00
  17. zscaler

    Zscaler Web Security, part of the Zscaler Cloud Security Platform, delivers the complete security stack as a cloud service, eliminating the cost and complexity of traditional secure web gateway appliances. By moving security to a globally distributed cloud, Zscaler brings the Internet and web gateway closer to the user for a faster experience. Organizations can easily scale protection to all mobile users or offices via local Internet breakouts, and minimize network and appliance infrastructure.

    ฿1.00
  18. ATEN THUNDER 940

      THUNDER  840
    APPLICATION THROUGHPUT (L4/L7) 10 Gbps / 7.5 Gbps
    LAYER 4 CPS 240k
    LAYER 4 HTTP RPS 1 million
    LAYER 4 CONCURRENT SESSIONS 16 million
    LAYER 7 CPS (1:1)*1 150k
    SSL BULK THROUGHPUT*2 7 Gbps
    SSL CPS*2|*3

    RSA(1K):2K

    RSA(2K):1K

    DDOS PROTECTION (SYN FLOOD) SYN/SEC 2 Million
    APPLICATION DELIVERY PARTITIONS (ADP) L3V 32
    NETWORK INTERFACES  
    1 GE COPPER 5
    1 GE FIBER (SFP) 0
    1/10 GE FIBER (SFP+) 4
    40 GE FIBER (QSFP+) 0
    100 GE FIBER (CXP) 0
    ฿1.00
  19. ATEN THUNDER 840

      THUNDER  840
    APPLICATION THROUGHPUT (L4/L7) 5 Gbps / 5 Gbps
    LAYER 4 CPS 200k
    LAYER 4 HTTP RPS 1 million
    LAYER 4 CONCURRENT SESSIONS 16 million
    LAYER 7 CPS (1:1)*1 50k
    SSL BULK THROUGHPUT*2 1 Gbps
    SSL CPS*2|*3

    RSA(1K):2K

    RSA(2K):500

    DDOS PROTECTION (SYN FLOOD) SYN/SEC 1.7 Million
    APPLICATION DELIVERY PARTITIONS (ADP) L3V 32
    NETWORK INTERFACES  
    1 GE COPPER 5
    1 GE FIBER (SFP) 0
    1/10 GE FIBER (SFP+) 2
    40 GE FIBER (QSFP+) 0
    100 GE FIBER (CXP) 0
    ฿1.00
  20. Radware Alteon NG 5208

    Alteon 5 Series

    Alteon D-5208, Alteon NG 5208

    • High performance SSL with support for latest encryption standards (i.e. ECC)*
    • High performance application delivery appliance covering wide throughput range: 6 to 26 Gbps throughput capacity
    • On-demand throughput scalability: 6, 12 & 26 Gbps throughput licenses
    • Supports ADC-VX with up to 24 vADCs
    • On-demand service scalability
    • 2 x 10 GbE SFP+, 8 x 1GbE RJ45
    • USB interface for software installation and recovery
    • Hot swappable Dual AC/DC power supply
    • Suitable for mid-size to large enterprises that require a high-performing solution
    • High performance compression, and caching
    • Front-to-back fans suitable for new data center design
    ฿1.00
  21. Radware Alteon NG 5224

    Alteon NG 5224

    Platform Highlights

    • High performance application delivery appliance covering wide throughput range: 5 to 16 Gbps throughput capacity
    • On-demand throughput scalability: 5, 10 & 16 Gbps throughput licenses
    • Supports ADC-VX with up to 24 vADCs
    • On-demand service scalability
    • 2 x 10 GbE SFP+, 16 x 1 GbE SFP, 8 x 1GbE RJ45
    • Two redundant management ports providing out-of-band highly reliable management interfaces with enhanced security
    • USB interface for software installation and recovery
    • Single or Dual AC/DC power supply
    • Suitable for mid-size to large enterprises that require a high-performing solution
    • Provides SSL acceleration, compression, and caching
    • Front-to-back fans suitable for new data center design
    ฿1.00
  22. F5 i4800

    Specifications i4800
    Intelligent Traffic
    Processing:
      L7 requests per second: 1.1M
    L4 connections per second: 450K
    L4 HTTP requests per second: 2M
    Maximum L4 concurrent connections: 28M
    Throughput: 20 Gbps L4/L7
    Hardware Offload SSL/TLS:   ECC†: 10K TPS (ECDSA P-256)
    RSA: 20K TPS (2K Keys)
    15 Gbps bulk encryption*
    FIPS SSL:   N/A
    Hardware Compression:   10 Gbps
    Hardware DDoS Protection:   N/A
    TurboFlex Performance Profiles   Tier 2
    Software Compression:   N/A
    Software Architecture:   64-bit TMOS
    On-Demand Upgradable:   N/A
    Virtualization (Maximum Number of vCMP Guests):   N/A
    Processor:   One 4-Core Intel Xeon processor (total 8 hyperthreaded logical processor cores)
    Memory:   32 GB DDR4
    Hard Drive:   1x 500 GB Enterprise Class HDD
    Gigabit Ethernet CU Ports:   Optional SFP
    Gigabit Fiber Ports (SFP):   8 SX or LX (sold separately)
    10 Gigabit Fiber Ports (SFP+):   4 SR/LR (sold separately); optional 10G copper direct attach
    40 Gigabit Fiber Ports (QSFP+):   N/A
    Power Supply:   1x 250W Platinum AC PSU (Additional PSU optional, 2x 650W DC PSU optional)
    Typical Consumption:   130W (single power supply, 110V input)**
    Input Voltage:   100-240 VAC +/- 10% auto switching, 50/60hz
    Typical Heat Output:   445 BTU/hour (single power supply, 110V input)**
    Dimensions:   1.72″ (4.37 cm) H x 17.4″ (44.2 cm) W x 30.6″ (77.72 cm) D
    1U industrial standard rack-mount chassis
    Weight:   20 lbs. (11.8 kg) (dual power supply)
    Operating Temperature:   32° to 104° F (0° to 40° C)
    Operational Relative Humidity:   5 to 85% at 40° C
    Safety Agency Approval:   ANSI/UL 60950-1-2014
    CSA 60950-1-07, including A1:2011+A2:2014
    IEC 60950-1:2005, A1:2009+A2:2013
    EN 60950-1:2006+A11:2009+A1:2010+A12:2011+A2:2013
    Certifications/
    Susceptibility Standards:
      ETSI EN 300 386 V1.6.1 (2012)
    EN 55032:2012 Class A; EN 61000-3-2:2014
    EN 61000-3-3:2013; EN 55024:2010
    FCC Class A (Part 15), IC Class A, VCCI Class A

    *Maximum throughput.
    **Please refer to the Platform Guide: i4000 Series for the latest power ratings for your specific configurations (dual power supplies, highline input voltage, DC, etc.).
    Notes: Performance-related numbers are based on local traffic management services only. Only optics provided by F5 are supported. SFP+ ports in i10800, i10600, i7800, i7600, i5800, and i5600
    are compatible with F5 SFP modules.
    † ECDHE-ECDSA-AES128-SHA256 cipher string tested.

    ฿1.00
  23. F5 i2800

    Specifications i2800
    Intelligent Traffic
    Processing:
      L7 requests per second: 650K
    L4 connections per second: 250K
    L4 HTTP requests per second: 1M
    Maximum L4 concurrent connections: 14M
    Throughput: 10 Gbps L4/L7
    Hardware Offload SSL/TLS:   ECC†: 3.5K TPS (ECDSA P-256)
    RSA: 4.3K TPS (2K Keys)
    8 Gbps bulk encryption*
    FIPS SSL:   N/A
    Hardware Compression:   5 Gbps
    Hardware DDoS Protection:   N/A
    TurboFlex Performance Profiles   Tier 1
    Software Compression:   N/A
    Software Architecture:   64-bit TMOS
    On-Demand Upgradable:   N/A
    Virtualization (Maximum Number of vCMP Guests):   N/A
    Processor:   One 2-Core Intel Xeon processor (total 4 hyperthreaded logical processor cores)
    Memory:   16 GB DDR4
    Hard Drive:   1x 500 GB Enterprise Class HDD
    Gigabit Ethernet CU Ports:   Optional SFP
    Gigabit Fiber Ports (SFP):   4 SX or LX (sold separately)
    10 Gigabit Fiber Ports (SFP+):   2 SR/LR (sold separately); optional 10G copper direct attach
    40 Gigabit Fiber Ports (QSFP+):   N/A
    Power Supply:   1x 250W Platinum AC PSU (Additional PSU optional, 2x 650W DC PSU optional)
    Typical Consumption:   95W (single power supply, 110V input)**
    Input Voltage:   100-240 VAC +/- 10% auto switching, 50/60hz
    Typical Heat Output:   325 BTU/hour (single power supply, 110V input)**
    Dimensions:   1.72″ (4.37 cm) H x 17.4″ (44.2 cm) W x 30.6″ (77.72 cm) D
    1U industrial standard rack-mount chassis
    Weight:   20 lbs. (11.8 kg) (dual power supply)
    Operating Temperature:   32° to 104° F (0° to 40° C)
    Operational Relative Humidity:   5 to 85% at 40° C
    Safety Agency Approval:   ANSI/UL 60950-1-2014
    CSA 60950-1-07, including A1:2011+A2:2014
    IEC 60950-1:2005, A1:2009+A2:2013
    EN 60950-1:2006+A11:2009+A1:2010+A12:2011+A2:2013
    Certifications/
    Susceptibility Standards:
      ETSI EN 300 386 V1.6.1 (2012)
    EN 55032:2012 Class A; EN 61000-3-2:2014
    EN 61000-3-3:2013; EN 55024:2010
    FCC Class A (Part 15), IC Class A, VCCI Class A

    *Maximum throughput.
    **Please refer to the Platform Guide: i2000 Series for the latest power ratings for your specific configurations (dual power supplies, highline input voltage, DC, etc.).
    Notes: Performance-related numbers are based on local traffic management services only. Only optics provided by F5 are supported. SFP+ ports in i10800, i10600, i7800, i7600, i5800, and i5600
    are compatible with F5 SFP modules.
    † ECDHE-ECDSA-AES128-SHA256 cipher string tested.

    ฿1.00
  24. FireEye NX 2500

      NX 2500
    User Count 1000 or 2500
    OS Support Microsoft Windows Mac OS X
    Performance Up to 100 Mbps or 250 Mbps
    Network Monitoring Ports 4x 10/100/1000 BASE-T Ports (in front panel)
    Network Ports Mode of Operation In-line Monitor, FailOpen, Fail- Close (HW Bypass) or TAP/SPANp
    High Availability (HA) Not Available
    High Availability (HA) Ports (rear panel) Not Available
    Management Ports (rear panel) 4x 10/100/1000 BASE- T Ports (in front panel)
    IPMI Port (rear panel) Rear Panel
    Front LCD & Keypad Not Available
    VGA Port Not Available
    Serial Port (rear panel) 115,200 bps, No Parity, 8 bits, 1 Stop Bit (RJ45 connector RJ45-to-Dsub adapter cable is included))
    Drive Capacity Single 1TB 3.5 inch SATA HDD, internal, fixed
    Enclosure 1RU, Fits 19 inch Rack
    Chassis Dimension WxDxH 17.2in(437mm) x 19.7in(500mm) x 1.7in(43.2mm))
    AC Power Supply Single 250 watt, 90-264 VAC, 3.5 - 1.5 A, 50-60 Hz, IEC60320-C14, inlet, Internal, Fixed
    Power Consumption Maximum (watts) 85 watts
    Thermal Dissipation Maximum (BTU/h) 290 BTU/h
    MTBF (h) 56,400 h
    Appliance Alone / As Shipped Weight lb. (kg) 16.2 lb (7.3 kg) / 28.2 lb (2.95 kg)
    Regulatory Compliance Safety IEC 60950 EN 60950-1 UL 60950 CSA/CAN-C22.2
    Security Certifications FIPS 140-2 Level 1 CC NDPP v1.1
    Regulatory Compliance EMC FCC Part 15 ICES-003 Class A AS/NZS CISPR 22 CISPR 32 EN 55032 EN 55024 IEC/EN 61000-3-2 IEC/EN 61000-3-3 IEC/EN 61000-4-2 V-2/2015 &V-3/2015
    Environmental Compliance RoHS Directive 2011/65/EU REACH WEEE Directive 2012/19/EU
    Operating Temperature 0 ~ 40°C 32 ~ 104°F
    Non-Operating Temperature --20 ~ 80°C -4 ~ 176°F
    Operating Relative Humidity 5% - 85% non-condensing
    Non-Operating Relative Humidity 5% - 95% non-condensing
    Operating Altitude 3,000 m 9,842 ft
       
    ฿1.00
ดูในมุมมอง ตาราง รายการ

รายการ 73-96 ของ 136

ตั้งค่าเรียงจากน้อยไปมาก
ต่อหน้า